Copyright: Amptek ADMCA Help File Version 1.0


Overview

The AMPTEK ADMCA Windows software provides control of the MCA8000A, DP4 and PX4.   This standard version is primarily display software although it can perform some basic analysis.  An additional Analysis module can be purchased which provides quantitative analysis using fundamental parameters.  Multiple copies of the program can be open at the same time and therefore simultaneous control of more than one MCA8000A is possible. Simultaneous control of more than one DP4 or PX4 is not supported at this time.

This help file provides help for all functions of the software, except the optional analysis package which has its own help file.  To open the Help file from the program go to the Help pulldown menu and select Help Topics.  Once in the Help file several options are available.  The Contents tab provides a table of contents of the help file and the Index tab provides an index of keywords.  Pop-Up Help is provided for the toolbar.  Context-sensitive help is available for the main display by clicking on the question mark in the toolbar [image] and placing it on the item for which help is desired.

Click here to see the definitions of the MCA8000A/DP4/PX4/DP5 software display.

Click here to see the updates to the DP4/PX4/DP5 Info Pane.

Click here for a description of the DP4/PX4/DP5 Info Pane updates.


File menu

File | Open (Ctrl+O)

Opens a saved data file.

File | Close All

Closes all opened spectra.

File | Modify

Opens the Modify Spectrum Properties dialog box.  This window allows for modification of the spectrum properties (tag, file name, description, contour styles, notes).

File |  Save

Saves the active spectrum .

File |  Save As (Ctrl+S)

Saves the active spectrum by opening the save as dialog.

File | Print (Ctrl+P)

Prints the spectrum display, info pane, select pane, and header information (file name, tag, description, time/date stamp, and notes if selected).  This is a standard windows print dialog.

File | Copy (Ctrl+R)

Copies the MCA channel data to the clipboard so that it can be pasted into other Windows applications.

File | Capture (Ctrl+C)

Copies the entire software display to the clipboard as a bitmap.

File | Capture Preview

Opens the Capture Preview window which shows the last screen capture.  If no previous capture exists, it will prompt for a capture.

File | Recent File

Lists up to the last four recently opened files.

File | Exit

Exits the ADMCA software.


View menu

View | Toolbar

Shows or hides the toolbar.

View | Status Bar

Shows or hides the status bar at the bottom of the software window.

View | Spectra List (<F6>)

Opens the Spectra List table.  This window lists all the spectra that are open in the display window.  This is where the active spectrum is set.

View | Spectra

Opens the Spectra dialog which sets the defualt tag names and contour styles for the first ten spectra that are opened or created.  It also sets the type of smoothing used (3 or 5 point).

View | Preferences

Opens the Review or Modify Preferences window. The Preferences dialog has four tabs: General, MCA, Analysis, and Plot.


MCA menu

MCA | Acquisition Setup (<F9>)

Opens the Set Acquisition Mode dialog box.  This dialog box sets all the acquisition parameters:  preset timer modes (real or live), preset time, peak modes (first or absolute), memory group number, threshold, and gain/ADC.

MCA | Start Acquisition / Stop Acquisition (<F3 or space bar>)

Starts or stops acquiring data depending on the current state of the MCA8000A. (see Start / Stop Acquisition)

MCA | Update From MCA (<F4>)

Updates all information in the Info Pane as well as data in the spectrum display from the MCA.

MCA | Delete Data (<D>)

Deletes the data from the current memory group in the MCA.

MCA | Reset Time (<T>)

Resets the Real and Live Counters and resets the preset timer to the preset value.

MCA | Delete Data and Reset Time (<A>)

Deletes data and resets the real and live counters.

MCA | Connect / Disconnect (<F2>)

Connects or disconnects the MCA to the host computer provided the COM Port and Baud Rate are set.  To set the COM port and Baud Rate open the Review or Modify Preferences dialog box and select the MCA tab.

MCA | Setup

Opens the MCA tab in the Preferences dialog.  This window sets the battery type, lock option, update interval, and COM Port settings for the MCA.  To lock the MCA enter in a 5 digit number.  This will lock the MCA from downloading data the next time it is turned on.  If the MCA has been locked and the software is started the dialog will prompt the user to enter the security code.  If the code has been forgotten, enter in 0.  This will unlock the MCA but will purge ALL data.


Display menu

Display | Info Pane

Info Pane | Font:  Sets the font for the Info Pane.

Info Pane | Background:  Sets the background color for the Info Pane.

Display | Select Pane

Select Pane | Font:  Sets the font for the Select Pane.

Select Pane | Background:  Sets the background color for the Select

Display | Plot Pane

Opens the Plot Pane View window which sets the display properties for the main spectrum window.

Display | All Panes

Shows the Info and Select Panes if they have been minimized.

Pane.

Display | Scale (<L>)

Scale | Lin:  Sets the scale to linear.

Scale | Log:  Sets the scale to logarithmic.

Scale | Sqrt:  Sets the scale to square root.

Display | Calibration (<F7>)

Toggles between calibrated and non-calibrated units on the x-axis (channel scale).


Analyze menu

Analyze | Calibrate (<F5>)

Opens the Calibrate dialog box.  To set a calibration enter the channel and value for at least two points.  Press Add after each point to enter that point into the calibration.

Analyze | Peak Search

Opens the Peak Search dialog box which performs a peak search on the spectrum over a specified range.

Analyze | Expression

Opens the Define Expression dialog box.  This dialog allows the user to perform mathematical operations on a spectrum or operations between spectra.

Analyze | Smooth:  Performs a smooth on the data as specified in the spectra dialog box. The spectra dialog can be opened from the View pulldown menu.

Analyze | Load Library

Loads a selected library for peak identification.

Analyze | Show Library

Displays a window which list the library points closest to the cursor position as set by the library sensitivity parameter.

Analyze | Define ROI

Opens the Define ROI dialog box.  This box sets the Regions of Interest (ROI) with the cursor or numerically.

Analyze | ROI Details

Opens the ROI Detail List which shows the peak informatin for all ROIs.

Analyze | Fundamental Parameters (optional module)

Starts the Fundamental Parameters (FP) Quantitative Analysis software.  See FP help file for more information

Analyze | Mini-X Controller (optional)

Starts the Mini-X Controller Application if installed.


Help menu

Help | Help Topics

Opens the Help File.  There are three different pages:  Contents, Index, and Find.  The Contents page displays the Help topics by subject.  The Index page provides an index of keywords of the help file.  The Find page creates a database of phrases from the help file for easier searching.

Help | Keyboard Map

Opens the keyboard shortcut dialog.  The user can right-click on this dialog and select copy or print to either copy the shortcuts to the clipboard or print the list of shortcuts.

Help | About

Open the About dialog box which displays version and date information as well as the serial number of the MCA8000A/DP4/PX4/DP5 if connected and the optional FP serial number and revision if ordered.


Modify Spectrum Properties

The Modify Spectrum Properties dialog box sets options for the active spectrum only.

To change the width of the contour line of the spectrum click on Width.

To change the color of the contour line click on Contour Color.

The Gain ADC of the spectrum is shown for reference.

To set the Tag click in the Tag field and type in a short string.  The Tag label is the identifier of the spectrum in the Spectra List and in the Info Pane.  The tag is also what is used to refer to a spectrum when defining expressions.  It is recommended to keep the tag as short as possible to facilitate defining expressions.  The Tag may not contain any spaces or symbols (/,\,+,=,-,*,|) and can be at most 16 characters in length.  Numbers must be at the end of the tag.  E.g.  “Pmca_test1” is acceptable where “Pmca test” and “1Pmca-test” are not acceptable.  The software will not let the user enter in an invalid tag.  If an invalid tag has been entered, a dialog will appear and the user can re-enter the tag.

To save a more complete description of the spectrum, use the Description field.  If lengthy or additional notes or descriptions are needed, click on the Additional Notes button.  The Notes are saved with the spectrum and can be printed with the spectrum if the Include Notes When Printing  box is checked.  Printing is restricted to one page, so when printing in landscape mode some notes may be cut if they are too lengthy.  When printing in portrait mode, there is plenty of room for elaborate notes.  The notes are saved with the spectrum, so the file size will depend on the amount of notes.  The description of the active spectrum is displayed in the title bar area of the software window along with the file name.  See screen definitions.

DP4 and PX4 settings can also be printed with the spectrum if the Include DP4/PX4/DP5 Settings When Printing box is checked.  The DP4/PX4/DP5 settings are saved with the spectrum and can be displayed by the Display Settings toobar button or menu item.

To change the file name of the spectrum, enter the name into the File Name field.

Toolbar shortcut:


Preferences - Plot Pane

The Plot Pane dialog sets the options for the spectrum window.

The Grid section sets the color and style of the grid as well as the type of grid displayed on the plot and whether to show tick marks with labels.  To change the color click on the color sample box.  To change the style, click on one of the listed styles.

The Cells box sets the number of cells used if the Grid Enable box or the Ticks Enable box checked.  The Horizontal and Vertical Cells settings determine how many grid boxes are shown and how many tick labels are shown on the plot.  The tick labels will often not display the same number of channels between each tick label.  This is due to rounding and the number of cells that are selected in the Cells box.  When exact channel position is required, move the cursor to the desired position and refer to the Select Pane for the exact channel.  The tick labels will switch to calibrated units when a calibration has been set.  When either the grid, ticks, or grid and ticks are enabled, they will print with the plot.

The ROI box sets the colors for the Regions of Interest (ROI).  The All check box enables all ROIs to be displayed.  The Selected check box highlights the ROI in which the cursor is currently.  To change the color of either the All or Selected ROI highlights click on the color sample.  If both the All and Selected check boxes are checked then all ROIs will be visible and the ROI that the cursor is on will be highlighted according to the colors set by the user.  If only the All check box is checked then all ROIs will be displayed the same way regardless of cursor position.  If only the Selected box is checked then only the ROI that the cursor is on will be displayed and the other marked ROIs will not be visible until the cursor is moved to their position.

Background sets the background color of the plot display window.  To change the color click on the color sample.

Plot Fill sets the color used to fill the area under the spectrum if Enable is checked.  If Enable is not checked then the plot will have no fill.  To change the color of the fill click on the color sample.

If the Auto Scale box is checked, the y-axis (vertical scale) will automatically scale.  The software does a check every update to see if the maximum value in a displayed channel exceeds the current vertical scale maximum.  If the condition is met, the y-axis will scale to twice the value of counts in that channel.  The spectrum will then “grow” once again until the max value is reached and the cycle repeats.

If there are any problems with software performance, disable the Auto Scale feature.

Toolbar shortcut:

NOTE:  To change the color and style of the contour line see the Modify dialog.


Review or Modify Preferences

This window enables the user to set or review General, Pocket MCA Setup, Analysis, and Plot user definable preferences.

General Tab

Pocket MCA Setup Tab

Analysis Tab

Plot Tab

At the bottom of the dialog there is a Defaults button.  This button reflects the current tab and can be used to return to the factory defaults.


Preferences - General

General Tab:Profile:  Picks the profile to use for the current session.  Different users can save their personal display preferences as different profiles.

Save on Exit:  Saves any changes that have been made in preferences and color schemes upon exiting the software.

Spectra Directory:  Sets the default directory for saved data.  If a path is entered here the software will always default to that directory to open a file.  If a   .\  (period backslash)  is left in the field, then the Open dialog will default to the last folder that was opened.

Spectrum Template:  Allows the user to automatically load a calibration or list of ROIs at startup and apply them to the live_data spectrum (the data coming from the MCA).  Indicate the file to use for the template in the Spectrum Filename field.

Show Start Dialog:  Check this box to use the start dialog when opening the software.  The dialog gives you the option to open a file or connect to the MCA when starting the program.


Preferences - Pocket MCA Setup

Pocket MCA Setup Tab:

Communication:  Sets the COM Port (COM1-9) and Baud Rate (115200 recommended) for communication with the MCA8000A.  If Connect on Startup is checked the program will automatically connect to the MCA8000A once it is opened.

Update:  Sets the interval at which the software updates the display information.  The interval should be no less than 0.2 seconds.  When the MCA is set in higher ADC Gain modes the updating of the display will be slower.  If the smallest interval is set then the MCA will update as quickly as it can.  In 16k ADC Gain mode the updating will be much slower.  It is recommended that the update interval be set to larger times in high ADC Gain modes (e.g. 4 sec for 4k ADC).  In general, 1 second per 1000 channels is recommended.  So, if the ADC Gain is set to 2048, set the update interval to 2 sec.  If Manual is checked then the MCA8000A must be manually updated from the MCA pulldown menu by selecting Update From MCA (<F4>)or by pressing F4.

When the plot display is zoomed in (i.e. not looking at all the channels), the software will only download the channels in the display.  So, if the ADC Gain is set to 1024, but the display is zoomed in to channels 100-350, only channels 100-350 will be requested from the MCA.  This is done to speed up the performance of the update when using large ADC Gains (and it is not necessary to view all channels all of the time).  If the user is zoomed in when using a large ADC Gain, the update interval can bet set faster according to the guidelines above.  If you are in ADC Gain mode 4096 but are zoomed in to channels 600-1600, the update interval can be set to 1 second since only 1000 channels are being requested (instead of the normal 4 sec for and ADC Gain of 4096).  The display will automatically zoom out and download all data when the Save/Save As are clicked.

MCA Setup:  Sets the security code for the MCA.  When the code is set, each time the MCA powers on, the user must enter the code to download any data from the MCA.  If 0 is entered, it will unlock the MCA but purge all data.  The Battery Type field is used to set the type of AA batteries that are being used.  This is so that the MCA can use the appropriate scale in displaying the battery life on the status bar.


Preferences - Analysis

Analysis Tab:

Peak Search/ROI

Background: The peak search routine and ROI info calculations perform background subtraction. You may set the number of points that the routine will use to fit a function to the background. The range of this parameter is 1 - 10 points.  In general, users use a smal number when the spectrum does not have a high background, and they use a larger number when the peaks are riding on a higher background.

Good Peak Value: The peak is considered valid after the background is subtracted and the Net Area exceeds the threshold set by the good peak level. The range of this parameter is 0 - 33,554,432. Good Peak Value must be entered as an integer value.  This is used in the ROI details table accessed from the Define ROI dialog and for the library to determine if the peak is accepatable when displaying the library label.

Sensitivity: The peak search routine sensitivity is set on a scale from 1 to 20, with 1 being the most restricted in the identification of peaks in the spectra. That is, the lowest sensitivity yields the most statistically significant peaks.  This is the same as the Sensitivity setting in the Peak Search dialog.  It can be set in either place. (see Peak Search for more details)

FWHM (Channels): The default setting for Peak Search FWHM is entered in this edit box.  The range for this parameter is an integer greater than or equal to 2.  This is the same as the Width setting in the Peak Search dialog.  It can be set in either place. (see Peak Search for more details)

FWHM Calc. Method: Sets the algorithm to use for the FWHM calculation.  Normal, Smoothing, Percent (%), or Gauss can be selected.  When Smoothing is selected, use the FWHM No. of Smooths fields to set either a 3-point or 5-point smooth.  The Smooth algorithm smooths the data in the ROI before calculating the FWHM.  This is adventageous when analyzing peaks with low count rates and total counts.  Note that when using smoothing, your are changing the data in the display, so the select pane will show the smoothed counts.  (Also see Peak Calculations.)

Centroid Calc. Method:  Selects the centroid calculation method.  See the Peak Calculations section for a description of the formulae used.

Library

Library:  Set the default directory for the library files, the default library to use if Load on startup is checked, and the Sensitivity of the library scan which determins how many library points are displayed when the Show Library function is called from the Analyze menu.  (see below)

Library files are ASCII text files that link a name to an associated unit/channel.  After a calibration has been done, a library can be opened to identify the ROIs that have been created. For example:  If the  Xray-Ka1.lib library is loaded, which lists Kα x-ray line energies, when the cursor is moved over an ROI the program will look up the centroid energy of the ROI in the library and display the tag associated with it.  So, if an ROI has a calibrated centroid of 6.4 keV and the above library is opened, the info pane will display Ka1 – Fe  6.4, which is the 6.4 keV line (ka1) of Iron (Fe).

Users may create their own libraries for use with PMCA. The library must list the values in the desired units followed by a comma. The values must be listed in ascending order. The label for the peak should follow the comma.

Repeat Measurements (MCA8000A/DP4/PX4/DP5)

Multiple spectrum measurements can be taken over a period of time.  Repeat Measurements along with presets determine how multiple spectrum measurements will be taken.

Repeat Measurements Setup

setup the acquisition device (MCA8000A/DP4/PX4/DP5)

connect to the device

verify the device is properly setup and can acquire a spectrum

stop the acquisition (start/stop button on the toolbar)

set a preset (stops the acquisition when repeat measurements is running)

configure the repeat measurement settings

  Repeat measurements controls.

Enable: Enables repeat measurements on the next start of acquisition. Repeat measurements are enabled for one series run only.  When completed the checkbox becomes unchecked.

File Save Directory: The directory where the repeat measurement files are stored.

Default Filename: Holds the default root filename.  The naming convention for the spectra file path is:

filesave_directory_path\filenameFILENUMBER.mca

For example:

filesave_directory_path = c:\plotsave

filename = testplot

Would generate:

c:\plotsave\ testplot01.mca

c:\plotsave\ testplot02.mca ...

Number of Loops: Holds the number of loops (acquisitions) requested for the repeat measurements test set.

Delay Between Loops: Holds the number of seconds delay between the test cycles.

Starting Time to Peak (DP4/PX4/DP5): Selects the initial pulse time to peak sequence value.  The Spectrum resolution tests begin at this value and increments through each larger value until all the values greater than or equal to the selected value have been tested or the number of loops has been exceeded.

Spectrum Resolution Test Option (DP4/PX4/DP5): Enables the spectrum resolution tests.

Repeat Measurements Results

Repeat measurents returns the spectrum plots (MCA files) and a SpectrumData.csv file.  SpectrumData.csv is in Comma Separated Values (CSV) file format.

SpectrumData.csv Fields:

Plot Filename

Date Time Stamp

Total Counts

Centroid

FWHM

Net Area

Uncertainty

Net Rate

Gross Area

Spectrum Resolution Test Results (DP4/PX4/DP5)

The spectrum resolution tests return the spectrum plots (MCA files) and a SpectrumResTest.csv file. SpectrumResTest.csv is in Comma Separated Values (CSV) file format.

SpectrumResTest.csv Fields:

Plot Filename

Date Time Stamp

Total Counts

Centroid

FWHM

Net Area

Uncertainty

Net Rate

Gross Area

Peak Time

Flattop


Spectra

The Spectra  dialog sets the default tag, and color and thickness of the contour for the first ten spectra that are created.  The type of smoothing is also set here.

Defaults:  Sets the default styles and tags for the first 10 spectra that are created or opened. To change a style or tag click on the sample of that spectrum.

Smooth:  Sets the smoothing function to either three (3) point or five (5) point average.  Smoothing is only performed on the data resident on the host computer, not to the data resident on the MCA8000A.  Smoothed data can be saved.  There is no unsmooth function available.  To return to the original unsmoothed spectrum, go to the Spectra List , right click on the original spectrum, and select Show.  You can then close or hide the smoothed spectrum by right-clicking on it in the Spectra list and selecting the appropriate action.


Set Acquisition Mode
Set Acquisition Mode (<F9>)

The Set Acquisition Mode dialog sets all of the acquisition related MCA parameters.  The default button on the botto of the dialog sets the MCA acquisition parameters to the factory default.

Acquisition Mode:

The standard acquisition mode of the MCA8000A is MCA or Multichannel Analyzer mode.  The MCA8000A was designed to be an MCA.  It creates a histogram of pulse heights over a particular voltage scale.

As added functionality, a limited MCS or Multichannel Scaling mode has been added.  This MCS mode is not a native function of the MCA8000A and is done through software on the PC side.  Once per update interval, the data from all the channels is downloaded and summed.  This summed value is then plotted in the display.  Therefore, what is displayed is the count rate per update interval.

Since it is not a native MCA8000A function, there are limitations to the accuracy and capability of the MCS mode.

Click here for more information.

Preset Mode:

The MCA8000A hardware supports only time realted preset modes, i.e. a Real Time of 60 seconds.  In order to give the user more felxibility, two other modes were introduced in software to facilitate particular tasks, preset total counts and preset channel counts.

Preset Mode - Seconds:

A Preset Mdoe of seconds uses either the Real or Live Timer for an acquisition (see Timer Type below).  This is an internal MCA function.  When a preset time of 60 seconds is entered, the MCA will acquire until exactly 60 seconds have elapsed (either real or live time) and then stop.  Enter the preset time in seconds in the Preset (sec) box.  The MCA8000A can be commanded to accumulate a spectrum over a preset time interval up to 16,777,215 seconds.  Entering a preset time of 0 disables the timers and allows the MCA to count indefinitely.  The preset may be changed in the midst of a data acquisition by the MCA8000A.

Note:  The time interval is not incremental. For example, if you select 60 seconds, the MCA8000A will collect data until reaching 60 seconds. If you then start the data collection again without clearing the time , the MCA8000A will collect data until either commanded to stop or as long as power is available.

Preset Mode – Counts:

When the Preset Mode is set to Counts, the MCA8000A timers are set to count indefinitely (a preset time of 0) and the software monitors the total counts in the spectrum.  When the total counts in the spectrum equal the user defined preset, the software sends a command to stop the MCA8000A acquisition.  Because this is a software controll and not in the MCA internal hardware, the software sends the command to stop when the correct counts have been achieved.  By the time the MCA receives the command from the PC and stops, some additional time will have elapsed resulting in additional counts above that specified.  Enter the total number of counts for the spectrum in the Preset (cts) box.

Preset Mode – Channel:

This mode is similar to the Counts mode except the software looks at a user defined channel for the appropriate amount of counts.  When that channel reaches the correct number of counts, the software sends a command to the MCA to stop. By the time the MCA receives the command from the PC and stops, some additional time will have elapsed resulting in additional counts above that specified.  Enter in the channel to use for the counts in the Channel (cts) box or press the cursor button to enter in the current cursor position.  Enter the counts for that channel in the Preset (cts) box.

Preset Mode - None:

A Preset Mode of None will disable all timers and counting mechanisms and set the MCA to count indefinitely.  This is equivalent to a Preset Mode of Seconds with 0 as the preset.

NOTE:  Because of a problem in the serial communications with Windows operating systems, an occasional refresh takes place that could confuse the Counts and Channel preset modes into stopping prematurely, i.e. before the designated number of counts.  The problem is most apt to happen when there is a very low count rate.  The Seconds preset (real and live) is internal to the MCA and therefore does not have the problem.

Timer Type:

Selects either the Real or Live timer for the Seconds Preset acquisition mode. The live time clock adjusts for dead time by turning off the clock whenever: a) the input signal exceeds the low level threshold, b) the analog pipeline is holding a pulse to be processed by the ADC, or c) if one or both of the MCA gates are active.

Timer Type and Preset Time (seconds, not counts or channel counts) settings are retained by the MCA after power off.  When the Live Timer is selected the Preset label will change to Preset (L), and likewise Preset (R) for the Real Timer.

Memory Group:

Sets the memory group used for data acquisition.  The MCA8000A has 32k of nonvolatile memory for storing up to 128 different spectra.  The number of memory groups available depends on the ADC Gain and is defined by 32k / ADC.  The group setting is retained by the MCA when powered off.

EXAMPLE:  When the ADC Gain is set to 8,192 there are four memory groups available, 0, 1, 2, and 3 (32k/8k = 4 groups).  Likewise for an ADC Gain of 256 there are 128 groups available.

Peak Mode:

Selects the Peak Mode to either First or Absolute.  First Peak mode is standard to nuclear instrumentation MCA’s.  Absolute Peak mode is typically used in airborne particle sizing analyzers, in environmental air monitoring systems, and in aerosol research.  Click here for figure.

Threshold:

The Threshold command sets the lowest channel of data collection in the MCA8000A. The maximum value of the threshold is half of the current ADC Gain. If a larger value than that is requested, the MCA8000A Software sets the threshold to half of the ADC resolution. The threshold may be chosen by entering the channel number in the edit box or by selecting Cursor.  The cursor must be positioned before opening the Acquisition Setup dialog.  When the cursor button is pressed, the software sets the threshold to the cursor channel position.  The threshold is retained by the MCA when powered off.  The threshold can be set without opening the acquisition dialog by pressing <F8> with the cursor at the desired threshold position.

ADC Gain:

Sets the ADC resolution. The ADC resolution may be set at seven different levels: 256, 512, 1024, 2048, 4096, 8192, and16,384.  The setting is retained by the MCA when powered off.  A gain of 1024 is common for most applications.

NOTE:  Increasing the ADC will slow down the communication between the host computer and the MCA due to more information being transferred over the serial interface.

Toolbar shortcut:


Multichannel Scaling (MCS)
MCA8000A Multichannel Scaling (MCS)

As added functionality, a limited MCS or Multichannel Scaling mode has been added.  This MCS mode is not a native function of the MCA8000A and is done through software on the PC side.  Once per update interval, the data from all the channels is downloaded and summed.  This summed value is then plotted in the display.  Therefore, what is displayed is the count rate per update interval.  The update interval is set in the Preferences – MCA tab.  The shorter the update interval, the more “spikes” will be seen.  See below.  The MCS mode has a maximum throughput of 50,000 counts per second.

Since it is not a native MCA8000A function (i.e. it is not calculated inside of the MCA8000A hardware), there are limitations to the accuracy and capability of the MCS mode.

Because the data is transfered through the RS-232 serial port, it is not consistent.  For example, a particular download may take 1.2 seconds, but the next one may take 1.4 seconds (due to the CPU of the PC doing other tasks).  This results in a larger count being displayed for that second update interval.  Therefore, the MCS mode should only be used to get a general and rough idea of the count rate over time.  In addition, there are some occasional refreshes that take place in the data buffer on the PC side.  These events cause sharp single channel spikes in the spectrum (see example plot).  These are not real changes in rate and must be ignored.  It is therefore not possible to trust changes from one channel or update interval to the next.  The user must wait for a few update intervals to be sure that the increase (or decrease)  is real (see example).

To decrease the affect of the spikes, increase the update interval and lower the baud rate in the Preferences – MCA dialog.  An update interval of 1 second and a baud rate less than 57600 will remove most of the timing related variations.  It also helps to close all other windows programs. When other windows programs are open, they share the CPU time.  When another application needs the CPU, it interrupts the Pmca application and affects the timing of the download which causes spikes.

Amptek does not guarantee the performance of the MCS mode.  It has been added to give the user a general and rough idea of what the count rate is doing over time.  It should not be used for any critical measurements.

MCS Operating Notes

To use the MCS mode, open the Acquisition Setup Dialog and select MCS from the first select box.  The MCS mode automatically disables acquisition options that do not apply to MCS.  After clicking on OK, start an acquisition by same methods as MCA mode (space bar, toolbar button etc…).  The spectrum will begin to accumulate.  The MCS mode uses 256 channels at a time for display and when the last channel has been used, the display “wraps around” and begins again at channel 0.  At the same time the software keeps a copy of the old data and when the acquisition is stopped, it re-creates the total accumulation as a separate spectrum in the second line of the spectra list.  The user may notice spikes or zero channels at the “seams” of where the software has joined the 256 channel passes together.  If the user wishes to save the data, make sure that the second line in the spectra list is the active spectrum (A next to it) and then save as you would an MCA spectrum.  If the user then wishes to do another accumulation, the software will prompt to save the data before it clears the buffers for the new acquisition.  The maximum accumulation time of the MCS mode is 16,384 seconds or roughly 4.5 hours.


DP4/PX4 Multichannel Scaling (MCS)
DP4/PX4/DP5 Multichannel Scaling (MCS)

The DP4/PX4/DP5 MultiChannel Scaler (MCS) is similar to the MCA except that each data channel corresponds to time instead of amplitude (energy), with the channel boundaries corresponding to start and stop times.  Each value in the array represents the total number of counts above the slow threshold during the appropriate time interval.

An MCS data acquisition is started with a given counting time per channel (X to X sec in the PX4).  The system records the number of counts in the first interval and places them in the first channel, and so on.  The PX4 uses the slow (shaped) channel counts for MCS. If the peaking time is set to its fastest (0.8 ms), then the MCS counts more closely resemble the input count rate. The MCS mode uses SCA8, so this gives the user the capability of setting the upper and lower level thresholds

Before You Start...

The region of interest (energy range) is set using SCA8.

Set SCA8 Low Channel to 0 and SCA8 High Channel to MCA Channels - 1.

0 to MCA Channels - 1 is the maximum range and is used for normal operation.

SCA8 MUST BE ENABLED AND SET FOR MCS TO RUN.

Running the DP4/PX4/DP5 MultiChannel Scaler

Set the Aquisition Mode to MCS.

Select a MCS Timebase.

Set the energy range in SCA8 (From 0 to MCA Channels - 1)

Enable SCA8.

Apply the configuration.

Stop the acquisition, if running.

Press the clear data button.

Start the MCS acquisition.

 MCS, Preset Count, and SCA8 Controls

MCS Hints:

Preset Counts also uses SCA8, the preset count controls can be used to set SCA8 channels.

Calibrate in MCA mode then set the region of interest.


Spectrum Display window

The spectrum display window displays the current live data as well as any other previously saved files or expressions.  The window displays each spectrum in its own range.  If one spectrum is 1024 channels long and another is 2048 channels long, they will both take up the maximum horizontal space in the window.  This allows for data taken in different resolutions to be compared.

In order to view the info and select pane information for a given spectrum it must be the Active spectrum.  To pick the active spectrum clcik on the Spectra List button [image] on the toolbar or go to the View menu and select Spectra List.  A box will open listing the spectra that have been loaded.  Click on the desired spectrum.  That spectrum will now have an A next to it in the spectra list indicating that it is now the active spectrum.  The live data stream from the MCA is always the first line in the spectra list.

Each spectrum can be displayed or hidden.  To hide a spectrum open the Spectra List box and right click on the spectrum you want to hide.  Then select Hide.  A hidden spectrum will have an H next to it in the spectra list.  If a spectrum is already hidden, then right click on that spectrum and select Show.  Even if a spectrum has been hidden, it can still be made the active spectrum (and viewed) by clicking on it in the spectra list.  If another spectrum is then made the active spectrum it will once again return to its hidden state.

To change the background colors, grid styles and spacing, and ROI colors open the Plot Pane window from the toolbar [image] or by going to the Display pulldown menu and selecting Plot Pane (also accessible from the preferences).

To change the scaling in the display window see Select Pane.

Note:  Keyboard commands will only work when the main spectrum display is the active window.  If the spectra list is open and active, the keyboard commands will not work.  All MCA8000A acquisition commands, such as start, stop, delete data, etc… only apply to the live date from the MCA.  If another spectrum is opened froma  file and the MCA is connected, the acquisition commands will still control the MCA.


MCA8000A Info Pane

The info pane displays status and ROI information for the active spectrum.  The Tag field displays the Tag of the spectrum.  To change the Tag of the active spectrum go to the File menu and select Modify.

The info pane displays the MCA status information:

Device:  Identifies the type of MCA that is currently connected, either MCA8000 or MCA8000A.  If the device is a DP4 or a PX4 see the DP4/PX4/DP5 status information.  If the software has been used only to open files and has not connected to an MCA, it will display PMCA.  If an MCA8000A is connected, the serial number of the unit will also be displayed.

Tag:  Tag of the active spectrum.

Mode: MCA or Limited MCS

Group:  Current memory group.

ADC Gain:  Current ADC resolution.

Threshold:  Current low level threshold channel number.

Preset Mode: Displays the current Preset acquisition mode.

Preset:  The preset acquisition time or counts.

Real Time:  Displays the real time counter.

Live Time:  Displays the live time counter.

Total Count:  The total number of counts in the spectrum.

Total Rate:  The total count rate of the spectrum (Total Count / Live_Time).

Start Time:  Displays the start time and date stamp.

Status:  The current condition of the MCA8000A (acquiring, stopped, disconnected).

Below the status information is the peak information of the selected ROI.  The selected ROI is the ROI that the cursor is presently on.

The Peak Information section displays:

Centroid:  The Centroid position of the peak.

FWHM:  The Full Width at Half Maximum resolution.

Net Area:  The Net Area under the peak.

Uncertainty:  The Net Uncertainty of the Peak.

Net Rate:  The Net Counting Rate under the peak.

Gross Area:  The Gross Area under the peak.

Library Label:  If a library is loaded the label will appear here.

Click here to view the equations used to calculate the above.

To change the background color or font of the info pane go to the Display pulldown menu and select Info Pane and then either Font or Background.  Or, right click and select Info Pane and then Font or Background.

The info pane can be changed to any desired width.  Move the cursor onto the border of the info pane and spectrum display to see the “sizing” cursor.  Click and drag the border to the desired position.


Select Pane

The select pane is located at the bottom of the display.  It displays the channel the cursor is in, counts in the current channel, range, and the scale for the Active spectrum.  At the right end of the Select Pane are the four range arrows (see below). Above the arrows is the Scale Label.  It reads LIN, LOG, SQRT depending on which scale the spectrum display is currently set.  To change the scale press L on the keyboard.

The range fields can be user defined by clicking on one of the range boxes, entering in the number and then pressing return.  The arrow buttons to the right of range fields increment the scale dimensions automatically.  The Up and Down arrows increase or decrease the Vertical Scale (same as up and down arrow keys on keyboard).  The Left and Right arrows expand or compress the Horizontal Range (same as the M and N keys on the keyboard, see keyboard shortcuts).  If the left mouse button is used to press the arrow buttons then the range fields will increment in large steps.  If the right mouse button is used the fields will increment in small steps.

The background color and font of the select pane can be changed by clicking on the Display pulldown menu and selecting Select Pane.  Or, right click and select Select Pane and then Font or Background.

The select pane can be changed to any desired height.  Move the cursor onto the border of the select pane and spectrum display to see the “sizing” cursor.  Click and drag the border to the desired position.


Keyboard Shortcuts

The top menus can be opened by pressing <alt> and the underlined letter of the menu.

Example:  To enter the File menu press <alt> and F.

The cursor can be moved by using the left and right arrow keys.

The vertical range can be changed by using the up and down arrow keys.  If another window is open and active or if the mouse is in a scale field in the select pane, the keyboard commands will not function.  For example, if the Spectra List is open and is the active window and the up and down arrow keys are used they will not adjust the scale of the spectrum, they will instead cycle through the spectra list.

Key	Function	Toolbar shortcut or Other Shortcut
→	Move cursor right	None
←	Move cursor left	None
↑	Expand vertical scale	None
↓	Compress vertical scale	None
Ctrl + →	Move cursor right to closest ROI	None
Ctrl + ←	Move cursor left to closest ROI	None
Space Bar	Starts / Stops data acquisition
A	Delete data and clear time clocks	None
D	Delete data
T	Clear time clocks
L	Cycle among linear, log, and square root scales	None
K	Move spectrum right	None
J	Move spectrum left	None
P	Move half of display page right	None
O	Move half of display page left	None
M	Compresses horizontal scale	Right Arrow Button on Select Pane
N	Expands horizontal scale	Left Arrow button on Select Pane
U	Mark ROI right	to enter the edit ROI state
Y	Mark ROI left	to enter the edit ROI state
Ctrl + Y	Unmark ROI right	to enter the edit ROI state
Ctrl + U	Unmark ROI left	to enter the edit ROI state
R	Clears all marked ROIs	None
E	Clears the ROI at the cursor position	None
F1	Help Contents	None
F2	Connects / Disconnects MCA
F3	Starts / Stops data acquisition (same as space bar)
F4	Updates data and time info	None
F5	Opens the Calibration dialog
Ctrl + F5	Runs Auto Calibration on the current spectrum	None
F6	Opens the Spectra List
F7	Toggles between calibrated and uncalibrated units in the Info and Select Panes
F8	Sets the Threshold at the present cursor position	None
F9	Opens the Acquisition Setup Dialog
Ctrl + C	Copies the Spectrum Window plot to the clipboard	File menu under Capture.
Ctrl + R	Copies the Active Spectrum Raw Data to the clipboard	File menu under Copy Spectrum
Ctrl + P	Prints the Spectrum Plot	File menu under Print Spectrum
Ctrl + S	Saves the Active Spectrum	File Menu under Save
Ctrl + E	Prints the Active Spectrum ROI list	ROI Details context menu Print Plot context menu Print ROI


Mouse Definitions

Clicking the left mouse button on the spectrum window will move the cursor to the position of the click.

A right mouse click will open the context pop-up menu which has shortcuts for various options.  If there is a check next to Edit ROI then the cursor is in the Edit ROI mode (see below).  If there is a check next to Select View then the cursor is in Select View mode (see below).  (See ROI and Select View for more information)

If the Edit ROI Toolbar button [image]  has been pressed then the mouse cursor will change to the ROI cursor.  Now, a left click and drag will create an ROI.  You will see the ROI being created.  (If the ROI is not filled while you are dragging see the Plot Pane help page.)  To edit the boundaries of an ROI click the cursor at the edge of the ROI and drag.  The cursor will change indicating that the boundaries are being changed.  To delete an ROI follow the instructions to edit the boundaries except drag the clicked boundary over the opposite boundary of the ROI.  You will see the ROI being erased as you drag.  To exit the ROI mark state press the Edit ROI toolbar button.  The cursor will now return to normal. The Edit ROI state can also be entered and exited by right clicking and selecting Edit ROI from the context menu.

If the Select View toolbar button [image] has been pressed, the cursor will change to the Select View cursor (cross hair).  Now, left click and drag the box to the desired boundaries.  The spectrum will now be zoomed to the selected box.  To exit the Select View mode press the Select View button on the toolbar.  The cursor will return to normal. The Zoom state can also be entered and exited by right clicking and selecting Select View.


Zoom
Select View / Zoom

Any part of the Spectrum Display window can be enlarged with the select view/zoom function.  Select this mode by pressing the Select View button on the toolbar [image] or by right clicking and selecting Select View.  The cursor has now changed to the cross hairs.  Left click and drag the box over the portion of the spectrum to be enlarged.  Release the button and the screen will zoom to the selection.  To go back to the previous spectrum view right click and select Previous View.  To view the entire spectrum again press the Full Horizontal Range button on the toolbar

Toolbar shortcut:


Regions of Interest (ROI)

A Region of Interest (ROI) is an area marked as a potential peak in a spectrum. Data channels marked as ROI channels are distinguished in the spectrum by a different color than that of unmarked channels.  To set the ROI color see Plot Pane.  If the cursor is placed between the boundaries of an ROI, that ROI’s peak information is displayed in the info pane.  The centroid of the peak, gross and net area under the peak, FWHM, uncertainty, and net rate are displayed.  If a library is opened then the label will appear below the Gross Area field.  To print a table of the ROIs open the spectra list, right click on the desired spectrum, and select Print ROI.  If the Define ROI dialog box is being used (see below), select Details, right click on the table, and select Print (select Copy to copy a bitmap image of the ROI table to the clipboard).

To mark a peak or region in a spectrum, first select that spectrum as the active spectrum, then press the Edit ROI button [image] on the toolbar or right-click on the screen and select Edit ROI.

The cursor will change to [image] signifying an ROI drag.

Drag the mouse to the right or left to mark the ROI. You will see the color of the marked region change. When you have completed marking the region, release the mouse button.  Once you have marked an ROI you can mark additional regions or exit the ROI mark state.  To exit the ROI mark state press either the Edit ROI button on the toolbar or right-click and select Edit ROI.

To delete an ROI with the mouse cursor you must be in the Mark ROI state as described above.  Click the left button at the edge of the ROI.

The cursor will change to [image].

Drag the mouse over the opposite boundary.  For example:  If you have clicked on the right boundary of an ROI, hold the left button down and drag the cursor over the left boundary of the ROI.  To delete an ROI with the keyboard, place the cursor in the ROI to be deleted and press E.

Use the same steps as above to change the boundaries of an ROI, but instead of moving the cursor over the opposite boundary, move in the direction of expanding the ROI or reducing the ROI.  Just make sure that you do not cross the opposite boundary when reducing the ROI because then you will unmark the ROI completely as described above.

ROIs can also be set numerically by channel by opening the Define ROI dialog box [image].  Here the user can input start and end channels for ROIs, remove them, and view a detail list with all the ROIs and their peak information.  With the Define ROI dialog open you can click on the spectrum to enter the channel boundaries (see Define ROI dialog).

Toolbar shortcut (to mark ROI):  Define ROI

 Edit ROI

Keyboard Shortcuts (to mark ROI):  U marks ROI to the right

   Y marks ROI to the left

U and Y can also expand an ROI that has already been set.  Place the cursor within an ROI and then use the U and Y keys to expand the boundaries.  U will expand the ROI to the right and Y will expand to the left.  <Ctrl> + U and <Ctrl> + Y will contract the ROI boundaries left and right respectfully.


Spectra List

The spectra list shows a list of the spectra that are currently open in the spectrum display window.  The spectra are listed by tag.  To change the tag go to the File menu and select Modify or use the toolbar shortcut [image].

The spectra list also allows the user to select the Active Spectrum.  To select the active spectrum, click on the tag of the spectrum in the list.  An A will appear next to the tag.  That spectrum is now the active spectrum.

Any spectrum can be hidden in the display provided it is not the active spectrum.  To hide a spectrum, right click on the tag in the spectra list and select Hide from the pop-up menu.  An H will appear next to the tag indicating that the spectrum is hidden.  To show a spectrum that is hidden, right click on it in the spectra list and select Show.

Right clicking a tag in the list also allows the user to save a spectrum, modify a spectrum, close a spectrum, print the ROI Detail list, or copy the ROI Detail list.

When performing a smooth, the original spectrum will become hidden and the smoothed spectrum will appear in the spectra list with the _SM3 or _SM5 extension added to the tag (depending on whether a 3 or 5 point smooth has been selected from the spectra dialog) and an E next to it showing that it is an expression.

Quick Reference for spectra list:

A = Active Spectrum

H = Hidden from view in the spectrum display

E = Spectrum is an expression

SM3_ =  Smoothed spectrum (3 point smooth)

SM5_ = Smoothed spectrum (5 point smooth)

NOTE:  A spectrum can be a combination of these parameters.  For example, a spectrum can be an expression and be hidden, in which case you will see HE.

Toolbar Shortcut:


Active Spectrum

The active spectrum is the only spectrum whose information is displayed in the Info and Select Panes.  Only the active spectrum’s area under the curve is filled according to the specifications of the Plot Pane View dialog.

If Smooth is selected from the Analyze menu, it only applies to the active spectrum.

In order to mark an ROI on a spectrum it must be the active spectrum.

Calibrations only apply to the active spectrum.  Therefore, if multiple spectra are open they will each need their own calibrations.

Changing the Modify Spectrum Properties dialog only affects the active spectrum.

TO SELECT THE ACTIVE SPECTRUM:

To select the active spectrum, open the spectra list either from the View menu or from the shortcut in the toolbar [image].  Click on the spectrum that you wish to be the active spectrum.  An A will appear to the left of the selected spectrum indicating that it is now the active spectrum.

HINT:  When multiple spectra are open, it is very useful to keep the Spectra List open.  This makes it much easier to see which spectrum is the Active Spectrum and keep track of which spectra are open.


Calibrate (<F5>)

The calibrate dialog lets the user set the calibration for the Active Spectrum.  To calibrate a spectrum the user must enter at least two points.  To enter a point, input the channel number and value for the point into the appropriate field.  Then press the Add button.  The Add button must be pressed for the calibration point to be entered.  You will see the calibration point added to the list below.  Pressing the Cursor button will input the channel number of the current cursor position into the channel box.  Pressing the Centroid button will input the centroid channel of the ROI that the cursor is presently on.  To view a plot of the calibration fit, press Plot.  If you wish to replace a certain value or channel number click on that calibration point with the mouse cursor.  Then enter in the new information in the Channel and/or Value boxes and then press Replace.  The calibration point will now be replaced with the new data.  If you wish to remove one or all of the calibration points, press the Remove or Remove All buttons respectively.

In the Units field enter in whatever label is desired for the calibration.  This label appears in the Select Pane.  The default is Channel.  It is most useful to enter in the units of the calibration.

Example:  Energy (keV).

There are two types of calibration equations that can be used.  One is a standard linear fit (which is the default for a two-point calibration) or a quadratic fit.  The quadratic fit is especially usefull when using detectors with non-linear responses.The Calibration equation is displayed at the bottom.  In x-ray detection for a linear fit, the A term represents the offset, and the B term the energy per channel.

Apply Calibration:

To apply a calibration of an existing spectrum to a new spectrum:

1.)  Load the calibrated file and the uncalibrated file if not already open.

2.)  Open the Spectra List from the toolbar [image] or from the View menu and make the calibrated file the active spectrum by clicking on it in the list.

3.)  Open the Calibrate dialog [image], you will see the calibration of the calibrated spectrum.  Make sure the Calibrate dialog is not covering the Spectra List.

4.)  Select the new spectrum in the Spectra List by clicking on it with the mouse cursor.

5.)  Press OK in the Calibrate dialog.

6.)  The Calibration of the old spectrum has now been applied to the new spectrum.

7.)  Close the Calibrate dialog box.

Toolbar shortcut:

Calibration On / Off: On

Off

Note:  The Calibration On / Off button is a toggle.  When it is displayed with a line connecting the dots the spectrum is not currently calibrated and if pressed will turn on the calibration.  When it is displayed with just dots the spectrum is currently calibrated and pressing the button will turn off the calibration.

The Auto Calibration section sets the calibration units and value as well as the auto calibration method.  In the Units field enter in whatever label is desired for the calibration.  This label appears in the Select Pane.  The default is keV.  It is most useful to enter in the units of the calibration.  In the Value field enter in the peak energy of the calibration source.  The default source is Fe55 which is 5.9 (keV).  In the Peak 2 Value field enter in the second peak energy of the calibration source.  The default source is Fe55, so the second peak defaults to 6.5 (keV).  The Method selection determines how the input the calibration channel is selected.  Centroid calculates the position of the calibration channel from the centroid of the region of interest.  Cursor sets the position of the calibration channel to the current cursor position.  2 Peak Centroid calculates the position of the calibration channel from the centroid of the region of interest of two peaks.  For more auto calibration information see Auto Calibration (MCA8000A/DP4/PX4/DP5).

  Auto Calibration controls.


Define ROI
Define ROI (Regions of Interest)

The Define ROI dialog allows the user to numerically enter the boundaries for the ROIs.  To enter the numbers simply click in the appropriate field and enter in the channel number.  Once both boundaries have been entered press Add and the ROI will appear in the list.  If Add is not pressed the ROI will not be entered into the list and will not appear on the spectrum.  The boundaries can also be selected by clicking the cursor on the appropriate channel on the spectrum display.  The first click will enter the lower limit of the ROI and the second click will enter the upper limit.  Once the boundaries have been selected press the Add button and the ROI will appear in the list.  If you wish to edit an ROI, click on that ROI in the list.  Then edit the points accordingly and press Replace.  When all desired ROIs have been entered press OK.

ROIs are only marked on the active spectrum.

To view a list of the ROIs and their peak information press Details.  This list can be printed or copied to the clipboard by right clicking anywhere on the table and selecting the appropriate action.

Apply ROI

ROIs from one spectrum can be applied to another spectrum.  To apply the ROIs from a source spectrum to a different spectrum follow these steps.

1.  Open the file that contains the ROIs you want to apply (can be the live data in which case it is already open).

2.  Open the file that you want the ROIs applied to (can be the live data if not selected in step 1)

3.  Open the Spectra List from the toolbar and position it on the left side of the screen.  Click on the spectrum that contains the ROIs to make it the active spectrum.  An “A” should appear next to that spectrum.

4.  Open the Define ROI dialog from the toolbar and place it on the left side of the screen.  You should be able to see both the Spectra List and the Define ROI dialog boxes.  The ROIs from the spectrum should be in the Define ROI list.

5.  Click on the spectrum that you want the ROIs applied to in the Spectra List.  An “A” should appear next to that spectrum.

6.  Click OK on the Define ROI dialog box.  The ROIs from the source spectrum have now been applied to the other spectrum.

Toolbar shortcut:  Define ROI


Peak Search

The peak search dialog sets the search parameters for the automatic peak search function.  The user can select the Range, the Width and Sensitivity of the peak search.

Peak Search Width:  The setting for the Peak Search FWHM Width is entered in this edit box.  The range for this parameter is any integer greater or equal to 2.  This is the same parameter that is set in the Preferences-Analysis dialog.  The value can be set in either location. (see note below)

Peak Search Sensitivity:

The peak search routine sensitivity is set on a scale from 1 to 20, with 1 being the most restricted in the identification of peaks in the spectra. That is, the lowest sensitivity yields the most statistically significant peaks.  This is the same parameter that is set in the Preferences-Analysis dialog.  The value can be set in either location.  (see note below)

Peak Search Entire Spectrum:

To peak search the entire spectrum select Search All.

Peak Search Range:

To peak search only a selected range enter in the boundaries for the search in the Range box.

After the type of search has been selected a table showing all the marked ROIs will appear.  Click on the x in the upper right of the table to close it.  Then click Add to ROI List to make the new peaks part of the ROI list.  If the user does not wish to make the new peaks part of the ROI list, press OK.

Toolbar shortcut:

NOTE:  Peak Search Method

The Peak Search is based on an analysis of the first derivative of the spectrum.  The numerical process of taking the first derivative from the spectrum is based on interpolation of every neighboring 5 points with a 2nd order polynomial.  This way some smoothing is implemented as well.

The first derivative obtained is tested for crossing the 0 (zero) from “+” to “-“ and for each such point two criteria are applied.  The first is the peak significance.  The absolute maximum of the derivative around the tested point is compared with a number supplied by the user – “sensitivity.”  If the maximum is below the sensitivity, the peak is rejected.  In the other case, the second test for peak width is applied.  The peak width from the first derivative, as a distance between two maxima around the point tested is compared with a user supplied value – “Width” (or FWHM).  If the calculated width is less than 0.5*Width or greater than 2*Width, the peak is rejected.  Otherwise, the peak is marked as a region of interest (ROI).  The ROI length is chosen to be 6 times the calculated peak width around the peak position.  If two neighboring peaks are too close, their ROIs are overlapped.

The user controls the peak search procedure by mainly changing the “sensitivity” value.  The smaller the value, the “bigger” and most statistically relevant peaks will be located.  The other value “Width,” should be appropriate for the spectrum being processed and can not control the peak search process precisely.


Define Expression

The define expression dialog allows the user to perform mathematical operations on a spectrum or between spectra.  The contour line Width and Color are user definable.  The operation can be performed over a specified gain/ADC.  In all cases, however, the operation starts with channel number zero (0). It is recommended that only spectra with the same gain/ADC be manipulated together.  The user can set the tag used for identification in the Spectra List and Info Pane, the file name, and a description.  To perform an operation, enter the expression in the expression field using the tag of each spectrum.

Remember to select the appropriate gain/ADC for the expression.

The following operations are defined:

+ : Addition

- : Subtraction

* : Multiplication

/ : Division

Example:  To multiply two spectra together with tags test1 and test2 over an ADC Gain of 1024, enter in (test1)*(test2) in the expression field and select 1024 in the ADC Gain pulldown.  To subtract the two spectra enter in (test1) – (test2).  Remember to select the correct ADC Gain.  The ADC Gain box does not default to the current ADC that the MCA is set.  Sometimes, the user may want to only manipulate a part of a spectrum.  In that case different ADC Gain selections can be used for the expression.

Toolbar shortcut:


Open File

The Open function reads an existing spectral data file that has been created by the MCA8000A software. If the file is opened successfully, the data and accompanying MCA8000A parameters are read into the active memory of the software. When Open is selected from the File menu or from the shortcut in the toolbar [image], the Open dialog box will appear. The filename may be directly entered into the File Name edit box or a file can be chosen from the available names in the list box. The default extension for the files in the list box will be *.mca. The filename entered in the File Name edit box must be located in the directory displayed in the Look in field. To change directories, select the folder from the directory tree.

To view ASCII files created in previous versions of MCA8000A software (mca8000a.exe for the HP200LX, pmca.exe for DOS, and pmca16k.exe old windows) select Spectra Data Files (*.asc; *.asp) from the Files of Type: list box.

.Bsp files from previous MCA8000A software can not be read by this software.  If *.bsp files need to be opened in this software, they must first be converted in the older software by saving them as *.asc files.

Files with the *.mca extension can be opened automatically from the windows file explorer or any shortcut by double clicking on the file name.  This will launch the Pmca software.  When the software opens the opening dialog will appear (if enabled).  Press cancel and the spectrum will appear.

Toolbar shortcut:


Save / Save As

Use the save as command to save and name the active spectrum. The software displays the Save As dialog box so you can name your document. The default extension for the files in the list box will be *.mca.  To change directories, select the folder from the directory tree.  To save a document with its existing name, directory, and file type, use the Save command from the File menu.

Click here for the MCA8000A file format .

WARNING:

If you have taken data and saved it and then deleted data from the MCA and take another spectrum, if you then attempt to save the new spectrum using the Save command you will overwrite your previously saved file because the file name has not been changed.  Use the Save As command to give the new data a file name.

Toolbar shortcut (save):


Amptek Spectrum File Format
Amptek Spectrum File Format (MCA8000A/DP4/PX4/DP5)

The Amptek Spectrum File Format file format is ASCII.  The fields are delimited in the MS-DOS format (return delimited).  If creating or modifying a file to be read by the ADMCA software using Microsoft Excel, it must be saved as Text (OS/2 or MS-DOS) (*.txt) format.

The files are saved with the *.mca extension and contain the following information in this format:

<<PMCA SPECTRUM>>

Tag

Description

<gen>

<sys>

<not>

ADC Gain

Threshold

Timer Mode

Preset Time

Live Time

Real Time

Start Time and Date

Serial Number

<<CALIBRATION>>

Label

Calibration points (channel   value)

<<ROI>>

Regions of Interest ranges (start channel   end channel)

<<DATA>

.

.

.

<<END>

Gain is defined on a scale of 0-6 corresponding to gains of 256-16,384.

Live Mode – 0 indicates the Real Preset Timer was used and Live Mode – 1 indicates the Live Preset Timer was used.

Sample File:

<<PMCA SPECTRUM>>

TAG – Am241

DESCRIPTION – Am241 Spectrum 4000 second. Accumulation

<gen> descriptions entered under Notes-General

<sys> descriptions entered under Notes-Type of System

<not> descriptions entered under Notes-Performance and Notes

GAIN – 2                   (indicating a gain of 1024)

THRESHOLD – 50  (indicating a threshold setting at channel 50)

LIVE_MODE – 0       (indicating the real preset timer was used)

PRESET_TIME – 4000         (in seconds)

LIVE_TIME - 3983.720000

REAL_TIME - 4000.000000

START_TIME - 10/20/1998 12:17:17

SERIAL_NUMBER - 1199

<<CALIBRATION>>

LABEL - Energy (eV)

1 0.000000

322 13950.000000

<<ROI>>

312 330

<<DATA>>

data points

<<END>>

DP4/PX4/DP5 Spectrum File Format Additional Features

Additional fields have been added to the original file format to accommodate the increase  in settings.  Old files can still be read and displayed.  When DP4 and PX4 spectrum files are saved, the current settings are saved with the file.

Two additional sections have been added after the data section (<<END>>):

<<DPP CONFIGURATION>> holds the DP4/PX4/DP5 configuration parameters.

<<DPP STATUS>> holds the status of the device when the file was saved.

Sample PX4 Configuration and Status:

<<DPP CONFIGURATION>>

COM Port: USB

Rise: 51.2uS

Top: 12.8uS

Fast Threshold: 34

PUR Enable: PUROff

RTD ON/OFF: RTDOff

RTD Threshold: 0.00% FS

RTD Fast HWHM: 10

AutoBaseline: Off

BLR: BLR:OFF

Acquisition Mode: MCA

MCS Timebase: 50mS/channel

MCA Channels: 1024

Slow Threshold: 3.71% FS

Buffer Select: Buffer A

Gate Input (TTL): GateOff

Preset: None

Coarse Gain: 17.46x

Fine Gain: 1.0000

Input Polarity: Negative

Input Offset: 0.037V

Pole Zero: OFF

Det Rst Lockout: 3.28mS

TEC: 219.9K

HV: 145.8V

Preamp Power: 8.5V

Analog Out: Shaped Pulse

Offset: 101mV

Aux: ICR

Audio: Off

<<DPP CONFIGURATION END>>

<<DPP STATUS>>

Device Type: PX4

Serial Number: 1070

Firmware: 3.11

FPGA: 3.11

Fast Count: 74643

Slow Count: 60470

Accumulation Time: 6375

Dead Time: 18.99%

HV Volt: 140V

TEC Temp: 243K

Board Temp: 30°C

<<DPP STATUS END>>


Live Data

The live data is the data that is presently being taken by the MCA8000A or data that has just been downloaded from the MCA.  It is always the first spectrum listed in the spectra list.  When the MCA8000A is connected, provided no other files have been opened, the live data is automatically the Active Spectrum.


Connect / Disconnect
Connect / Disconnect (<F2>)

To connect to the MCA8000A the COM Port and Baud Rate must first be set in the Review or Modify Preferences dialog box.  To open the dialog go to the View menu and select Preferences.  Then click on the tab labeled MCA.  Once the COM port and baud rate have been set, press the Connect / Disconnect button [image] on the toolbar or select Connect from the MCA menu.

To disconnect from the MCA8000A press the Connect / Disconnect button [image] on the toolbar or select Disconnect from the MCA menu.  The disconnect verification dialog will appear.  Press OK to disconnect

The MCA pulldown menu changes its contents depending on if the MCA8000A is connected or not.  If it is not connected it will display Connect.  If it is connected, it will display Disconnect.

Note:  The Connect / Disconnect toolbar button displays the current state of the MCA.  When the computer and MCA are connected with a line [image] it indicates that the MCA is connected and if you press the button it will disconnect the MCA.  When there is no line connecting the MCA and the computer [image] the MCA is not connected and pressing the button will connect the MCA.

Toolbar shortcut:  	Connect

Disconnect


Start / Stop
Start / Stop (<space bar> or <F3>)

Start:

Starts acquiring data if the MCA8000A is connected and not already taking data.  If the MCA8000A is not connected it will attempt to connect and proceed with the acquisition.  The MCA8000A will take data according to the parameters in the Acquisition Setup dialog box.  This dialog sets the threshold, gain, group, peak mode, timer mode, and preset time. When data acquisition is started, the MCA8000A automatically marks the data with the date and time.

The response of the MCA8000A might take a few seconds. Once the MCA8000A accepts and executes the command, the Status light will blink.

The MCA8000A will collect data for the specified data collection interval once Start is commanded and as long as power is available, regardless of whether the host computer continues to be connected to the MCA or not (see stand alone mode). The Start function also resumes a data collection interval interrupted by a Stop acquisition.

Stop:

The Stop command stops data acquisition in the MCA8000A.  If the MCA is not connected and a Stop command is sent, the software will attempt to connect and stop the data acquisition.

Note:  The Start / Stop button displays the action to be performed.  A green light [image] indicates that the MCA8000A is stopped, so pressing the button will start data acquisition.   A red light [image] indicates that the MCA8000A is currently taking data and pressing the button will stop data acquisition.

Toolbar shortcut:  Stop

         Start


Stand Alone Mode
Stand-Alone Mode

The MCA8000A can operate in stand-alone mode, not connected to any host computer.  The MCA enters this mode after data acquisition is started by the host computer and then the host computer is either turned off or disconnected from the MCA8000A.  In this stand-alone mode the MCA will acquire data until the preset acquisition time (real or live) is reached.  This mode is useful when power is not always available for the host computer.  The MCA’s batteries also last longer in this mode because the serial port is not active and does not use as much power from the batteries.

Once the spectrum is acquired, the MCA waits approximately 2 minutes for a connection with the host computer.  If there is no connection attempt from the host computer, the MCA powers down with the spectrum stored in memory.  The spectrum can then be downloaded from the MCA the next time it is connected to the host computer.


MCA8000A Hardware

Description:

The MCA8000 incorporates a number of modules, . These modules include: 1) Input range selector and linear gate unit; 2) Peak-hold circuitry; 3) Sampling successive approximation ADC; 4) MCA control unit; 5) Microcontroller; 6) RS-232 interface; 7) Power supply; 8) Low level discriminator (LLD); and 9) Nonvolatile memory. A host computer is used to configure and operate the MCA as well as to manage the obtained spectral data.  Click here for block diagram.

Input:

The MCA8000 accepts positive, shaped unipolar or bipolar input pulses with peaking times as short as 250 nsec. The amplitude range of the input can be either 0 to +5V or 0 to +10V. The range is selected with the Input Range Switch (5V/10V switch).

The input impedance is 200 k for the 0 to +5V range and approximately 2 kohms for the 0 to +10V range. The MCA input circuitry is protected for DC signals with amplitudes up to 15V and for pulsed signals with amplitudes up to 30V. The input protection diodes reduce the input impedance of the MCA8000 to 0.5 kohms and 1 kohms for the 0 to +5V and 0 to +10V ranges, respectively, when the input signal exceeds the selected range or the MCA is not powered.

When the linear gate is switched, the capacitive load changes and a small amount of charge is injected into the input network . When the MCA8000A input is driven by an amplifier with higher output impedance, a small perturbation of the input signal can occur when the linear gate switches. However, this perturbation occurs after the peak of the pulse and does not affect the pulse-height measurement.

Peak-hold Circuit:

The peak-hold circuit accepts positive pulses with peaking times as short as 250 nsec (100 nsec shaping times). The peak-hold circuit is based upon the Amptek PH300 hybrid circuit. A peak detect signal is generated when the input pulse peak amplitude is reached. This peak amplitude is then held at the output of the circuit. After approximately 2 usec following peak detection, the sample-and-hold circuit of the ADC samples the output voltage of the peak-hold circuit. Immediately following this sampling, the peak-hold circuit resets and is ready to accept another pulse for processing.

Analog to Digital Converter (ADC):

The successive approximation ADC digitizes the pulse amplitude in less than 5 μs. If a second pulse arrives while another pulse is being processed, it is held by the peak-hold circuit. The second pulse is processed after the ADC has completed digitizing the first pulse. Because of this two-stage storage, the dead time following a single pulse can be as short as 2 μs. The use of the sliding scale technique maintains differential linearity to better than ±0.6% frpm 50mV to full scale. The sliding scale technique reduces the ADC range at the top end by 1/32.

MCA Controller:

The MCA control unit manages the MCA functional blocks and the storage of spectra. This unit synchronizes the low level discriminator (LLD), the peak-hold detector, the ADC, and the nonvolatile memory. The MCA control unit and the microcontroller provide the timing and gating functions of the MCA8000A.

Low Level Discriminator:

The low level discriminator (LLD) sets the minimum pulse amplitude for acceptance of input signals. The threshold is software controlled and can be set as high as half of the selected input range (half of the selected ADC resolution). The threshold parameter is stored in the nonvolatile memory.

Logic Gates:

There are two TTL compatible logic gates available for gating the input pulses. Gate 1 is active HIGH TTL and Gate 2 is active LOW. When either input is active, the analog input pulses are gated off and the live clock is stopped. The active state of this signal must occur at or prior to the peak of the analog pulse and must extend for at least 1 μs after the peak. When not connected, these inputs are held in the inactive state by internal resistors.

Host Computer Interface:

The MCA8000A connects to a host computer via an RS-232 interface I/O. This connection is provided via a null modem cable as shown in the MCA8000A Data Transfer Protocol. When the MCA8000A serial port is connected to a powered host computer via this interface, the serial port is active. The power consumption for the MCA8000A increases when this port is active. To optimize battery consumption, operate the MCA8000A in stand-alone mode without an active serial port.

Power:

The MCA8000A is powered by either two AA batteries or an external power supply. When operating on external power via the adapter, there is no drain on the AA batteries or recharging of the batteries. The MCA8000A has a built-in battery capacity meter that supports alkaline and NiCad batteries. To select the appropriate battery type, use the MCA Setup dialog.

To change the batteries, first turn off the MCA8000A. Then remove the battery cover, change the batteries, and replace the battery cover. The  correct battery polarity is indicated on the bottom of the battery compartment. The MCA8000A has built-in protection for reverse installed batteries. When the MCA8000A will not be used for more than one month, it is recommended that the batteries be removed to increase the battery life.  There is approximately 30 μA discharge current from the batteries when the MCA8000A is not powered.

The MCA8000A can also be powered by an external power source with voltage between +9 and +12V.  The external power supply can be connected and disconnected while the MCA8000A is running from batteries. This soft power switching allows uninterrupted operation of the MCA8000A when switching from battery to external power and vice versa.


Technical Specifications

Performance Characteristics

Pulse-Height Digitizer: Successive-approximation ADC with two-stage input analog pipeline and sliding-scale linearization. Software selectable resolution: 16k, 8k, 4k, 2k, 1k, 0.5k and 0.25k channels. The sliding scale technique reduces the ADC range by 1/32.

Pulse Processing Time: Minimum pulse peaking time is 250 ns. Acquisition time of the analog pipeline 2 μs. ADC conversion time 5 μs.

Differential Nonlinearity: < ±0.6% over full scale.

Integral Nonlinearity: < ±0.02% over full scale.

Gain Stability: Gain < ±10 ppm/deg C; Zero drift < ±3 ppm/deg C.

Low Level Discriminator: Software selectable threshold, in increments of one channel, up to half of full range. Threshold accuracy <±0.5 % of full range.

Memory: Nonvolatile, 10 years data retention.

Maximum Counts per Channel: 4.29 x 10^9 counts (4 bytes).

Timers: Real and Live Timers.  Data acquisition real or live time preset in multiples of one second.  Maximum preset time 16,777,215 (2^24 - 1) seconds.

I/O Interface: Serial, high speed 115.2 kbps. Software selectable baud rates:  9.6 kbps, 19.2 kbps, 57.6 kbps, 115.2 kbps.

Power: The MCA8000A has an automatic power-down function when operating on battery power which turns the power off whenever the MCA is not acquiring data or exchanging data with a computer.  If the MCA is powered via an external power adapter or the data acquisition is active while on battery power, the automatic power-off function is disabled.

Power Consumption:  < 300 mW in data acquisition mode with active serial interface, < 250 mW in data acquisition mode with inactive serial interface (stand-alone mode).

Power sources:  Two AA batteries or 9 V (200mW) AC adapter (included) 3.5mm x 1.3mm Female Barrel; Center positive. When operating on external power via the adapter, there is no drain or recharging of the internal batteries.

Battery types:  Any type of AA battery, including:  alkaline, Lithium, rechargeable NiCad or NIMH, or any battery set with appropriate capacity and voltage range from 2 to 7 V.

Protection:  Built-in protection against incorrect battery polarity.

Power monitor:  Battery discharge monitor for alkaline and NiCad batteries.

Battery Life (typical): From a set of two alkaline batteries - 24 hours in stand-alone acquisition mode with inactive serial port, 16 hours in acquisition mode with active serial port.

Operating Temperature: 0 to 50 deg C.

Controls and Indicators

ON/OFF Button:  ON/OFF button toggles the MCA8000A power between ON and OFF.

Status Light:  Steady red light indicates that the MCA power is ON and no data acquisition in progress. Flashing red light indicates MCA in data acquisition mode.

Input Range Switch:  Switch sets the dynamic range of analog input pulses at 0 to +5 V or 0 to +10 V.

Connectors

Input:  The analog input accepts positive unipolar or bipolar semigaussian pulses of shaping time constant > 100 ns (peaking time > 250 ns). The dynamic range of the analog pulses is 0 to +5V (Z = 200k) or 0 to +10V (Z = 2k), selectable by the Input Range Switch. The input has overload protection up to +15V.  The DC level of the input signal must be zero.

Gate 1:  Active HIGH TTL compatible logic gate. When this input is HIGH, the analog input pulses are gated off and the live clock is stopped. The active state of this signal must occur at or prior to the peak of the analog pulse and must extend for at least 1 us after the peak. When not connected, this input is held inactive by an internal pull-down resistor.

Gate 2:  Active LOW TTL compatible logic gate. When this input is LOW, the analog input pulses are gated off and the live clock is stopped.  The active state of Gate 2 must occur at or prior to the peak of the analog pulse and must extend for at least 1 us after the peak. When not connected, this input is held inactive by an internal pull-up resistor.

The Input, Gate 1, and Gate 2 connectors are LEMO, S series receptacle, style 00, female.

Interface (I/O):  DB-9 male RS-232 connector.  This connector requires a null modem cable (included) to connect to a computer.

Power:  The MCA8000A power connector mates to a center positive, 3.5 mm x 1.5 mm female barrel connector.

Mechanical

Weight:  < 300g (including set of alkaline batteries).

Dimensions: 6.5 x 2.8 x 0.8 / 165 mm x 71 mm x 20 mm.


MCA8000A Data Transfer Protocol

MCA8000A Data Format

Spectral Data Structure

The counts in each channel (further referred as channel data) are accumulated in a long integer variable, 4 bytes long.  The first two bytes form the lower word while the higher two bytes form the upper word of the channel data.  The maximum channel number of a single spectrum is 16,384.

MCA Status Data Structure

The Status Data Structure provides information for the current status of the MCA.  Every time the MCA8000A sends data to the computer the entire status structure is updated.  The status of the MCA8000A is reported in 20 bytes.  The format of the status structure is shown below.  The first byte of the status structure transmitted is DataChkSum_3 while the last transmitted byte of the structure is the CheckSum byte:

8 bit Status structure

DataChkSum_3…first transmitted

DataChkSum_2

DataChkSum_1

DataChkSum_0

PresetTime_2

PresetTime_1

PresetTime_0

Battery

RealTime_2

RealTime_1

RealTime_0

RealTime_75

LiveTime_2

LiveTime_1

LiveTime_0

LiveTime_75

Threshold_1

Threshold_0

Flags

CheckSum…last transmitted

DataChkSum_0 to DataChkSum_3 represent a  32 bit unsigned integer variable DataChkSum. DataChkSum_0 is the least significant byte. DataChkSum is either the sum MOD 216 of all bytes of the channel data that were transmitted at the last data exchange preceding the transmission of the status structure, or is the current group number and the serial number of the MCA8000A unit.

PresetTime_0 to PresetTime_2 bytes form a  24 bit integer variable that is the preset acquisition time of the MCA8000A in seconds.  PresetTime_0 is the least significant byte.  The value of the PresetTime can be modified by the PRESET TIME COMMAND.

Battery is a single byte value that represents the MCA8000A battery voltage or indicates the use of an external power source.  If Battery is equal to 0 then the MCA8000A is powered by an external power source.  The table below shows the Battery value vs. Remaining battery capacity for Alkaline (3V) and NiCd (2.5V) batteries:

Remaining Capacity	Battery Value
[%]	Alkaline (3V)	NiCd (2.5V)
< 5	< 50	< 68
12.5	63	73
25	68	74
37.5	71	75
50	74	76
62.5	77	77
75	80	78
> 87.5	> 88	> 80

The four bytes from RealTime_0 to RealTime_75 are used to calculate the elapsed real acquisition time.  The real time is calculated as:

RealTime = 216 * RealTime_2 + 28 * RealTime_1 + RealTime_0 +(1 – (RealTime_75/75)

The first three terms give the integer part of the elapsed time in seconds.  The last term is a fractional part that increments in 1/75th of second.  The elapsed live time is calculated similarly to the RealTime using the four bytes from LiveTime_0 to LiveTime_75.  Both real and live elapsed time cannot be modified by the host computer.

Threshold_0 and Threshold_1 form a 16 bit unsigned integer that represents the low level threshold of the MCA8000A.  The threshold is given as a channel number and should not exceed half of the currently set resolution of the MCA8000A.

The Flags byte contains information about various parameters of the MCA.  This byte can be modified from the host PC.  The Flags bit assignments are as follows:

bit Flags.2 to bit Flags.0:	ADC Resolution (Spectrum Length :000b = 16k, 001b = 8k, 010b = 4k,  011b = 2k, 100b = 1k, 101b = 0.5k, 110b = 0.25k )

bit Flags.3 :	Timer flag  ( 1 = Live, 0 = Real )

bit Flags.4:	Start/Stop (1 = Start, 0 = Stop )

bit Flags.5:	Security Flag (1 = MCA Protected, 0 = MCA Public )

bit Flags.6:	Main Battery Type (1 = NiCad , 0 = Alkaline,)

bit Flags.7:	Backup Battery Condition (1 = Bad, 0 =OK,  )

CheckSum is a byte that contains the sum MOD256 of the 19 status bytes - from Flags to the DataChkSum_3.

MCA8000A Start Stamp Structure

The Start Stamp Structure provides the acquisition start time and start date of the current MCA group.  Every time the acquisition of the MCA8000A is activated, the computer must set the start time and the start date.  The start stamp of the MCA8000A is reported in 8 bytes.  Each byte contains a packed BCD number.  For more details see the START TIME COMMAND, START DATE COMMAND and GET START STAMP COMMAND.

8 bit Start Stamp structure

Century 	(packed BCD 19 or 20)	last transmitted byte.

Year	(packed BCD 0 to 99)

Month	(packed BCD 1 to 12)

Day	(packed BCD 1 to 31)

NotUsed

Hours 	(packed BCD 0 to 23)

Minutes	(packed BCD 0 to 59)

Seconds	(packed BCD 0 to 59)	`first transmitted byte.

MCA8000A Commands

Command Format

The host computer (PC) controls the actions of the MCA8000A and the data flow from/to MCA8000A using a number of commands.  Each command is sent as a packet of 5 bytes.  The command bytes are defined as follows:

Byte 0	Command code, this byte indicates the specific action that MCA8000A has to take.

Byte 1-3	These 3 bytes contain data that support the command code and/or set various parameters of the MCA8000A (e.g. time, threshold)

Byte 4	Check sum byte, the sum of bytes 0 to 3, MOD 256.

Byte0 is sent first while Byte4 is the last byte in the command queue.

SEND DATA AND CHECK SUM COMMAND (Command Code = 0)

This is a command sent to the MCA that causes the MCA to respond by sending data back to the PC.

Byte 0	0

Byte 1,2	These two bytes form an integer (Byte 1 lower byte) that represent the relative address of the first byte of either the lower word or the  upper word of the first channel of the current group to be transmitted from MCA.

Byte 1,2 word is calculated as (channel# * 4 + n), where n is variable that is 0 for transfers of the lower word of the channel  data, and n is 2 for transfers of the upper word.

Byte 3	Must be zero and included in the check sum.

Byte 4	Check sum byte.

When this command is issued the received DataChkSum is the sum MOD 216 of all bytes of the channel data that were transmitted from the MCA to the computer at the last data exchange preceding the transmission of the status structure. This variable may be used as a check sum of the transmitted channel data.

SEND DATA, GROUP AND S/N COMMAND (Command Code = 16)

This is a command sent to the MCA that causes the MCA to respond by sending data back to the PC.

Byte 0:	16

Byte 1,2	These two bytes form an integer (Byte 1 lower byte) that represent	 the relative address of the first byte of either the lower word or the upper word of the first channel of the current group to be transmitted from MCA.

Byte 1,2 word is calculated as (channel# * 4 + n), where n is a variable that is 0 for transfers of the lower word of the channel data, and n is 2 for transfers of the upper word.

Byte 3	Do not care, but must be non-zero and included in the check sum.

Byte 4	Check sum byte.

When this command is issued, the received DataChkSum_0 is the current group number (byte). DataChkSum_2 and DataChkSum_3 form a unsigned integer that represent the serial number of the MCA devices connected to the computer.

GET START STAMP COMMAND (Command Code = 48)

This is a command sent to the MCA that causes the MCA to send back the eight bytes of the Start Stamp Structure.

Byte 0:	48

Byte 1,2,3	do not care, but must be non-zero and included in the check sum.

Byte 4	check sum byte.

The MCA responds to this command by sending the Start Stamp Structure

first transmitting Seconds. Century is transmitted last.  For details on synchronizing the data flow from MCA to the computer refer to Data Exchange Sequence section of this document.

SET START DATE COMMAND (Command Code = 19HEX or 20HEX)

This is a command sent to the MCA that causes the MCA to store the start date in the Start Stamp Structure. .  MCA will accept this command only if the MCA is not acquiring data, otherwise the command will be ignored.

Byte 0:	19HEX for the 20th century date.  20HEX for the 21st century date.

Byte 1,2,3	Year, Month, and Day, these three bytes represent packed BCD numbers. See Start Stamp Structure.

Byte 4	check sum byte.

SET START TIME COMMAND (Command Code = 37)

This is a command sent to the MCA that causes the MCA to store the start time in the Start Stamp Structure.  MCA will accept this command only if the MCA is not acquiring data, otherwise the command will be ignored.

Byte 0:	37

Byte 1,2,3	Hours, Minutes, and Seconds, these three bytes represent packed BCD numbers. See Start Stamp Structure.

Byte 4	check sum byte.

SET GROUP COMMAND (Command Code = 17)

This is a command that sets the MCA memory group. will accept this command only if the MCA is not acquiring data, otherwise the command will be ignored.

Byte 0:	17

Byte 1	0

Byte 2	Group Number

Byte 3	do not care, but must be non-zero and included in the check sum.

Byte 4	check sum byte.

The Group Number depends on the ADC resolution and can be: 0 or 1 for 16k, 0 to 3 for 8k, 0 to 7 for 4k, 0 to 15 for 2k, 0 to 31 for 1k, 0 to 63 for 0.5k, 0 to 127 for 0.25k.

SET MCA LOCK COMMAND (Command Code = 117)

This is a command that sets the MCA security lock number.  The two byte (int) lock number is used to unlock the MCA after power up or after long periods of taking data in local mode. Refer to the users manual for details about locking and unlocking the MCA.

Byte 0:	117

Byte 1,2	Lock number.

Byte 3	do not care, but must be non-zero and included in the check sum.

Byte 4	check sum byte.

CONTROL COMMAND (Command Code = 1)

This command configures the MCA8000A according to the bits in the Flags byte. This command also sets the threshold.  To take a specific action the Flags byte  and the Threshold setting must first be retrieved from MCA8000A using the SEND DATA COMMAND.  Once Flags and Threshold values are obtained they can be modified and send back to the MCA8000A.  For example, if the threshold does not have to be changed, then send as byte 2 and byte 3 the threshold word obtained from MCA8000A Status structure..

Byte 0:	1

Byte 1	Control flags (Flags byte)

Byte 2	lower byte of the threshold value.

Byte 3	upper byte of the threshold value.

Byte 4	check sum byte.

PRESET TIME COMMAND (Command Code = 2)

This command sends the preset time value (acquisition time) to the MCA8000A.  This is either live time or real depending on timer flag (bit Flags.3 of the Flags byte).

Byte 0	2

Byte 1	First (lowest) byte of the preset time

Byte 2	Second byte of the preset time

Byte 3	Third byte of the preset time

Byte 4	check sum byte.

NOTE: This command does not affect the timer type (live or real) that controls the acquisition.

DELETE COMMAND (Command Code = 5)

Deletes either data, time, or both time and data.

Byte 0:	5

Byte 1	1 = delete data, 0 = do not delete data

Byte 2	1 = delete time, 0 = do not delete time

Byte 3	do not care, but must be non-zero and included in the check sum.

Byte 4	check sum byte.

Data Exchange Sequence

The data transfer between the MCA8000A and the host PC is accomplished via asynchronous serial connection (RS 232).  The serial controller data format is: 8 data bits, one stop bit, one party bit.  MCA8000A sends a parity bit set to zero.  It is recommended to set the parity mode of the serial controller to “Space Parity”.  Even or Odd Parity settings may be used.  In this case, however, the parity error generated by the serial controller must be ignored.  MCA8000A baud rate is set by the host software (See BAUD RATE SETTING MODE). The wiring diagram of the serial cable connecting PC and MCA8000A is shown in this figure.

Further in the text the signal nomenclature of the RS-232 PC port is used.  The names of the signal lines are referred to the PC connector.  Normally the serial port Receive Data (RxD) and Transmit Data (TxD) signals of the IBM compatible PC are inverted.  Similarly the RxD and TxD lines of the MCA8000A are inverted.

The PC acts always as a master while the MCA responds always as a slave.  The PC port output signal RTS is used by the PC to indicate the direction of the data transfer.  RTS = HIGH indicates data transfer from PC to MCA (mode SEND), while RTS = LOW sets the data transfer direction from MCA to the PC (mode RECEIVE).  The MCA constantly monitors the PC RTS line and responds accordingly.  The action of the PC depends on the selected mode: SEND or RECEIVE.  The DTR and DSR signals are used to synchronize the data streams from/to MCA8000A.

SEND MODE

In this mode PC sends commands to the MCA.  Each command sent to MCA consists of five bytes (see earlier section).  The sequence to send a command is as follows:

1.  Read and save the state of the DSR signal (DSR bit of the modem status register MSR of the UART).  Assume DSR is stored as variable OLDDSR.

2.  Clear DTR signal of MCR

3.  Set RTS signal high (RTS bit of the modem control register MCR of the serial port)  It is recommended that 2 and 3 are done simultaneously by a single output to the MCR register..

4.  Point to the first byte of the command sequence.

5.  Reset and start a Time-Out Timer (Watch Dog).  Allow 110 to 165 ms (2 to 3 clock ticks on IBM compatible PC) for sending a single byte.

6.  Check if Transmit Holding Register is empty.  If not wait until it becomes empty or exit with time-out error (10).

7.  Check if the DSR signal has been complemented.  If DSR is different than OLDDSR. Then store DSR in OLDDSR and send the current byte from the command queue.  Point to the next command byte in the command sequence and go to point 5 above.  If DSR does not change for the time-out period exit with time-out error (10).

8.  After the last byte of the command has been sent wait until DSR changes its state indicating that the MCA has received the last byte, the check sum of the command bytes is OK, and the command code is recognizable.  Check the time-out timer.  If time out expired exit with time-out error (10).

9.  If all of the command bytes have been sent successfully read (dummy) the Receive Buffer of the UART and then clear RTS.  If the last command sent is a command that prepares MCA for sending data (SEND DATA COMMAND, SEND DATA, GROUP AND S/N COMMAND, GET START STAMP COMMAND), set high the DTR bit in MCR; otherwise keep DTR = LOW. Allow 100 to 200 ms or more before sending next command  (see NOTE).

10.  If time-out expires set RTS = LOW.  Allow 100 to 200 us before sending next command.

NOTE  A command may not be sent successfully due to various reasons.  The MCA8000A might be physically disconnected (missing, bad or wrong serial cable), turned off or improperly configured (baud rate).  In all these cases multiple attempts to send the same command will fail through.  Under some circumstances, particularly after the delete command has been sent, the MCA may need more time to respond (up to 2 seconds) and few subsequent attempts to send the command may be unsuccessful.  It is, therefore, desirable to try at least 10 times sending a single command, before deciding that something is wrong with the MCA connection.  It is important to clear RTS for at least 100 us between the consequent attempts to send the same command.

The algorithm for sending a command to the MCA8000A is illustrated in this flowchart.

RECEIVE MODE

PC enters this mode after SEND DATA COMMAND.  The sequence to receive a byte is as follows:

1.  Check if there is a byte received by the serial port or if interrupts are used an interrupt is generated when a byte has been received.

2.  Get and store the byte from the serial port.

3.  If the byte received is not the last expected byte from the MCA8000A alternate DTR indicating that the PC is ready to receive data.

4.  If the byte received is the last expected byte do not alternate DTR and disable interrupts in case of interrupt transfer.

The MCA8000A always sends first the 20 bytes of the MCA8000A status structure.  If the check sum of the status bytes is OK the PC may store the status information.  After the status information has been received the MCA8000A starts sending the channel data in packets of two bytes - the lower or the upper word (see Channel Data and Send Command).  First is send the lower byte of the channel data word.  The PC can interrupt the data transfer from MCA8000A to the PC at any time by setting the RTS line HIGH.

NOTE:  MCA keeps sending data as long as PC enables the data transfer from MCA to the PC by keeping RTS LOW and alternating the DTR signal.  Therefore, it is the PC responsibility to monitor and control the data transfer between the MCA8000A and the PC.

BAUD RATE SETTING MODE

MCA8000A sets its default baud rate upon power on to 4800 bps.  To set the desired communication baud rate (greater than 19.2 kbps is recommended) a procedure for setting the baud rate must be performed. The maximum baud rate is 115.2 kbps, all other baud rates that are obtained by dividing 115.2 by an integer number (divisor) can be used with MCA8000A.  The divisor is a byte that is equal to 1 for the 115.2 kbps.  To set the baud rate either of SEND DATA COMMAND or SEND DATA, GROUP AND S/N COMMAND must be issued.  In this case Byte 3 of the command bytes must contain the divisor value corresponding to the desired baud rate.  The serial port must be configured for 4800 bps.  The sequence to set the baud rate is as follows:

1.  Set the UART for 4800 bps and store the desired baud rate divisor in Byte 3 of the command sequence bytes.

2.  Read and save the state of the DSR signal (DSR bit of the modem status register MSR of the UART).  Assume DSR is stored as variable OLDDSR.

3.  Simultaneously set RTS and DTR signals high (RTS and DTR bits of the modem control register MCR of the serial port

4.  Point to the first byte of the command sequence.

5.  Reset and start a Time-Out Timer (Watch Dog).  Allow 110 to 165 ms (2 to 3 clock ticks on IBM compatible PC) for sending a single byte.

6.  Check if Transmit Holding Register is empty.  If not wait until it becomes empty or exit with time-out error (10).

7.  Check if the DSR signal has been complemented.  If DSR is different than OLDDSR. Then store DSR in OLDDSR and send the current byte from the command queue.  Point to the next command byte in the command sequence and go to point 5 above.  If DSR does not change for the time-out period exit with time-out error (10).

8.  After the last byte of the command has been sent wait until DSR changes its state indicating that the MCA has received the last byte, the check sum of the command bytes is OK, and the command code is valid.  Check the time-out timer.  If time out expired exit with time-out error (10).

9.  If all of the command bytes have been sent successfully read (dummy) the Receive Buffer of the UART, set the UART for the desired baud rate and then clear RTS.  Set high the DTR bit in MCR.  Allow 100 to 200 ?s or more before sending next command

10.  If time-out expires clear RTS and DTR.  Allow 100 to 200 ?s before new attempt to set the baud rate.

MCA8000A REMOTE POWER ON

The MCA8000A may be powered on remotely by a host computer through the RS-232 interface.  The Power-On interface utilizes the host computer’s “Data Terminal Read” (DTR) and “Request to Send” (RTS) outputs to generate a control signal in the MCA.  To power the MCA on:

1.  Hold RTS high (>4V).

2.  While RTS is high, drive DTR with an approximate square wave:

Frequency:  1kHz to 200 kHz

Duration:  >50ms

Amplitude:  >4Vpp

This can be accomplished in software by toggling the DTR for 50 ms while RTS is high.

Power Down:

In order to save battery life, the MCA8000A has an automatic Power-Down feature.  It will automatically Power-Down if it is not acquiring data and is not communicating with the host computer for a period of approximately 3 minutes.

When in battery mode and not acquiring data, in order to avoid automatic Power-Down, the customer written software should communicate with the MCA8000A at least once every 2 minutes.


DOS Software

The MCA8000A also comes with DOS software.  This software was designed to run the HP 200LX Palmtop computers for ultra portability and power efficiency. The PMCA DOS Software allows data acquisition and display on any IBM PC compatible computer, including desktops, notebooks and palmtops.  This software supports region of interest, energy calibration, peak search, peak information, MCA8000A configuration, and file management.

The PMCA Software acquires and displays all data transmitted by the MCA8000A and provides configuration management of the MCA8000A, including:  spectral data, elapsed real and live time, and status parameters and flags. Among the primary tools in PMCA Software is an automatic peak search routine which marks the identified peaks as ROIs.  Peak counts and FWHM are automatically calculated and displayed in either channels or user-defined calibration units. On-line Help documents the available features in PMCA Software.

When the MCA8000A and the host computer are linked, the PMCA Software is in Remote mode. This mode is identifiable by both the Power indicator and the MCA Group number indicator in the lower right corner of the PMCA display. Local mode results when the PMCA Software is operating without an active link to an MCA8000A. The lower right of the PMCA Software display will then read Local.

See the MCA8000A Dos Software User’s Manual (available in pdf format and included on the CD) for more information on the DOS software.


MCA8000A Dynamic and Object Link Libraries (APIs)
MCA8000A Communication Libraries (APIs)

PMCA COM is an Application Programming Interface Library for the Amptek Pocket Multichannel  Analyzers MCA8000 and MCA8000A.  PMCA COM runs on personal computers under any of Win32 operating systems (Windows 95/98/ME/2000/NT/XP, or Windows CE with user required modifications).  Application programs invoke PMCA COM functions to establish communication with PMCA, control its operation, and retrieve data.

PMCA COM is distributed in two forms, as an object link library (.LIB) or Dynamic Link Library (.DLL). The application executable programs (.EXE) are created by linking the application code with one of these libraries statically or dynamically (see Microsoft documentation about program linking).  The applications can be developed in C, Visual Basic or any other language.

PMCA COM API functions have the prefix  Pmca  and usually include action verbs and the names of items to which the actions are related (e.g. PmcaGetData).  All functions return an integer type value representing either the requested parameter or error code.  All error codes are negative.  The error can be a PMCA COM error or a system error. PMCA COM error codes have bit 28 set in accordance with the Win32 convention (see Microsoft documentation).  The C language representation of PMCA COM functions is defined in the PmcaCom.h header file.  The PMCA COM errors are defined in PmcaErr.h. These files are provided with the PMCA COM libraries.

There are only a few functions that do not require communication between the PMCA and the host. The majority of  functions initiate some kind of  interaction with PMCA.  These functions may take a long time to execute.  PMCA COM provides two versions of functions that require interaction with PMCA: synchronous and asynchronous.  Synchronous functions do not return to the calling procedure until the operation is complete.  Asynchronous functions return to the caller immediately and execute the operation in background.  This allows for better response of applications to other tasks, e.g. user interface tasks.

Asynchronous functions have an additional parameter, a pointer to the field that will receive the result of the operation on the function completion.  All other parameters are identical to those in synchronous functions.  The asynchronous function returns the identifier of the request.  The application can poll the result filed to find out about the operation status or it can later suspend itself and wait until the operation completion by calling  the PmcaWait function.  The following lines illustrate the use of asynchronous functions:

int result;

int waitStat;

int stat = PmcaAsyncGetGain(&result);	// stat receives request id

if (stat > 0)

{

.

.	Do something

.

waitStat = PmcaWait(stat);

if (waitStat >= 0)	// gain value is stored in result

}

Before any interaction with the PMCA (excluding power up) can take place, the application program must call the PmcaConnect function.  The PmcaPowerUp function must be called before PmcaConnect if  the PMCA is not powered manually.

When the PMCA is connected, PMCA COM creates two threads of execution, EXEC and MONITOR.  The EXEC thread executes requests for interaction with PMCA.  These requests are generated by PMCA COM API functions and are placed in the EXEC queue.  The EXEC thread retrieves requests from its queue and executes them one at a time.  Usually the EXEC thread runs on a relatively low priority to allow other processes and threads to perform their important tasks. The application can change the EXEC thread priority by calling the PmcaSetPriority function. The priority has seven levels from 0 to 6, with level 0 corresponding to Win32 priority THREAD_PRIORITY_IDLE and level 6 - THREAD_PRIORITY_TIME_CRITICAL (see Microsoft documentation for details). The MONITOR thread runs with a high priority. Its function is to prevent the EXEC thread from CPU time starvation. Most of the time the MONITOR thread is inactive. It periodically wakes up and checks whether the EXEC task requires more CPU time to perform its operations. If so it temporarily boosts the EXEC thread priority to THREAD_PRIORITY_HIGHEST.

The EXEC and MONITOR threads are terminated when PmcaTerminateCom is called. The application should call PmcaTerminateCom before exiting the program.

PMCA COM data types

PMCA COM data types define special values and layout of records used in exchange of data between the host computer and the PMCA. These data types are declared in PmcaCom.h file.

PmcaDeviceType is an enumerator that defines types of PMCA devices. An object of this type can have one of the following values:

PMCA_AUTO_DETECT

PMCA_8000

PMCA_8000A

PMCA_AUTO_DETECT value is used only in PmcaConnect call to request automatic identification of the attached device.

PmcaBatteryType identifies type of main battery. Valid values are

PMCA_LI	- alkaline

PMCA_NICAD	- nickel-cadmium

PmcaFlagsType contains some information about the state of PMCA. The following is its C language declaration:

typedef union

{

    struct

    {

        unsigned char gain:3;	// Gain index from 0 to 6 (gain 16,384 to 256)

        unsigned char live:1;	// Live timing when set, otherwise real

        unsigned char acquire:1;	// PMCA is acquiring data (when set)

        unsigned char secure:1;	// PMCA is protected (when set)

        unsigned char batteryType:1;

        unsigned char batteryCondition:1;	// Battery is bad (when set)

    } bits;

    unsigned char byte;

} PmcaFlagsType;

PmcaFlagsType is a part of PmcaControlType:

typedef struct

{

PmcaFlagsType   flags;

unsigned short  threshold:15;

unsigned short  absolutePeak:1;

} PmcaControlType;

In turn, PmcaControlType is a part of PmcaStatusType. PMCA sends the status information to the host in this format:

typedef struct

{

    unsigned char   checkSum;

PmcaControlType control;

    unsigned long   liveTime75:8;

    unsigned long   liveTime:24;

    unsigned long   realTime75:8;

    unsigned long   realTime:24;

    unsigned long   battery:8;

    unsigned long   presetTime:24;

    union

    {

        unsigned long checkSum;

        struct

        {

            unsigned short  group:10;

            unsigned short  spare:6;

            unsigned short  serialNumber;

        } gsn;

    } u;

} PmcaStatusType;


Description of PMCA COM API functions

Get Device Type

C declaration:

PmcaDeviceType PmcaGetDeviceType(void);

Return: type of attached device.

Comment: this is the only function that does not return integer; the function always succeeds.

Set Priority

C declaration:

int PmcaSetPriority(int priority);

Sets priority of the EXEC thread.

Input:	priority

Ranges from 0 to 6 (corresponds to Win32 priorities THREAD_PRIOTITY_IDLE to THREAD_PRIORITY_TIME_CRITICAL)

Return:	error code (always PMCA_ERROR_SUCCESS)

Cancel (request)

C declaration:

int PmcaCancel(int id);

Cancels a request that has been previously initiated by an asynchronous procedure call.

Input:	id - request identifier that was returned when an asynchronous function was called

return:	error code

errors:

PMCA_ERROR_REQUEST_NOT_FOUND - either the request has been already completed or the identifier is invalid

Wait (for request completion)

C declaration:

int PmcaWait(int id);

Suspends the application thread until the request is completed.

Input:	id - request identifier that was returned when an asynchronous function was called

return:	result of the operation or error code

errors:

PMCA_ERROR_REQUEST_NOT_FOUND - either the request has been already completed or the identifier is invalid

Disconnect

C declaration:

int PmcaDisconnect(void);

Disconnects PMCA from the communication port and releases it

return: error code

Terminate

C declaration:

int PmcaTerminateCom(void);

Terminates communication threads

return: error code

Power Up

C declaration:

int PmcaPowerUp(int port);

int PmcaAsyncPowerUp(int *result, int port);

Turns on PMCA power.

Input: 	port - communication port number PMCA is connected to.

return: error code

Connect

C declaration:

int PmcaConnect(int port, int baudRate, PmcaDeviceType device);

int PmcaAsyncConnect(int * result, int port, int baudRate, PmcaDeviceType device);

Establishes communication with PMCA

Inputs:

port 	- communication port number

baudRate 	- requested baudRate (must between 1200 and 115200)

device	- PMCA device type; if device is PMCA_AUTO_DETECT the system attempts to identify the device

return:	error code

Get serial number

C declaration:

int PmcaGetSerialNumber(void);

int PmcaAsyncGetSerialNumber(int *result);

Retrieves the serial number of the attached device

return:	serial number or error code

Get battery type

C declaration:

int PmcaGetBatteryType(void);

int PmcaAsyncGetBatteryType(int *result);

Checks the main battery type in  PMCA

return:	battery type or error code

Get battery condition

C declaration:

int PmcaGetBatteryCondition(void);

int PmcaAsyncGetBatteryCondition(int *result);

Checks the backup battery condition in  PMCA

return:	battery condition or error code

Get battery capacity

C declaration:

int PmcaGetBatteryCapacity(void);

int PmcaAsyncGetBatteryCapacity(int *result);

Checks the remaining capacity of the main battery  in  PMCA

return:	percentage of the remaining battery capacity or error code

Get group

C declaration:

int PmcaGetGroup(void);

int PmcaAsyncGetGroup(int *result);

Retrieves the current group

return:	current group or error code

Get gain

C declaration:

int PmcaGetGain(void);

int PmcaAsyncGetGroup(int *result);

Returns the current gain

return:	current gain or error code

Get real time

C declaration:

int PmcaGetRealTime(void);

int PmcaAsyncGetRealTime(int *result);

Retrieves the value of the real time counter from PMCA (in ms)

return:	real timer value or error code

Get live time

C declaration:

int PmcaGetLiveTime(void);

int PmcaAsyncGetLiveTime(int *result);

Retrieves the value of the live timer from PMCA (in ms)

return:	live timer value or error code

Get flags

C declaration:

int PmcaGetFlags(PmcaFlagsType *flags);

int PmcaAsyncGetFlags(int *result, PmcaFlagsType *flags);

Retrieves PMCA flags structure from PMCA

output:	flags

return:	error code

Get status

C declaration:

int PmcaGetStatus(PmcaStatusType *status);

int PmcaAsyncGetStatus(int *result, PmcaStatusType *status);

Retrieves PMCA status structure from PMCA

output:	status

return:	error code

Get data

C declaration:

int PmcaGetData(unsigned long *buffer, int channel, int count);

int PmcaAsyncGetData(int *result, unsigned long *buffer, int channel, int count);

Retrieves data from specified memory group.

input:	channel – starting channel

count – number of channels to retrieve data from

output:	buffer

return:	error code

NOTE:  It is possible to retrieve data from higher groups than the present group.  Set the starting channel parameter to the last channel of the current group.  Then set the count parameter for the desired number of channels.  This will download the last channel of the current group (which can be ignored) and the specified channles in the next group or groups.  For example, if the MCA8000A is presently in 1024 channel mode and in group 0 and the PmcaGetData(buffer, 1023, 2049) command is sent, the MCA will download the last channel of  group 0, all of group 1, and all of group 2.  There is no way to download data from previous memory groups (e.g. being in the group 1 and downloading data from group 0).

Get date and time

C declaration:

int PmcaGetDateAndTime(char *dateTime);

int PmcaAsyncGetDateAndTime(int * result, char *dateTime);

Retrieves time stamp and stores it in dateTime buffer as MM/DD/YYYY HH:MM:SS

output:	dateTime - character buffer at least 20 characters long

return:	error code

Set absolute peak mode

C declaration:

int PmcaSetAbsolutePeakMode(void);

int PmcaAsyncAbsolutePeakMode(int *result);

Defines the data acquisition mode as absolute peak detection

return:	error code

Note:  The MCA8000A defaults to first peak mode on power up.  If absolute peak mode is the desired mode of operation, the set absolute peak mode command must be sent every time the MCA8000A is powered on.

Set first peak mode

C declaration:

int PmcaSetFirstPeakMode(void);

int PmcaAsyncFirstPeakMode(int *result);

Defines the data acquisition mode as first peak detection

return:	error code

Note:  First peak mode is the default state of the MCA8000A when it is powered on.  The first peak mode command only needs to be sent if the MCA8000A has been switched to abolute peak mode since the last time it was powered on.

Select real timer

C declaration:

int PmcaSelectRealTimer(void);

int PmcaAsyncSelectRealTimer(int *result);

Selects real timer for data acquisition

return:	error code

Select live timer

C declaration:

int PmcaSelectLiveTimer(void);

int PmcaAsyncSelectLiveTimer(int *result);

Selects live timer for data acquisition

return:	error code

Clear data

C declaration:

int PmcaClearData(void);

int PmcaAsyncClearData(int *result);

Clears data in the current group

return:	error code

Clear time

C declaration:

int PmcaClearTime(void);

int PmcaAsyncClearTime(int *result);

Resets acquisition time in the current group

return:	error code

Clear data and time

C declaration:

int PmcaClearDataAndTime(void);

int PmcaAsyncClearDataAndTime(int *result);

Clears data in the current group and resets acquisition time

return:	error code

Start acquisition

C declaration:

int PmcaStartAcquisition(int setStamp);

int PmcaAsyncStartAcquisition(int *result, int setStamp);

Starts acquisition and if setStamp parameter is not zero sets start time stamp to current time

input:	setStamp - if not zero start stamp will be set to current time

return:	error code

Stop acquisition

C declaration:

int PmcaStopAcquisition(void);

int PmcaAsyncStopAcquisition(int *result);

Stops acquisition

return:	error code

Note:  The MCA8000A can not be stopped sooner than one second after the start command has been sent.  If the stop command is sent sooner than one second after the start command the MCA8000A will stop at one second.

Set group

C declaration:

int PmcaSetGroup(int group);

int PmcaAsyncSetGroup(int *result, int group);

Selects the specified group as the current group

input:	group

return:	error code

Set gain  (ADC resolution)

C declaration:

int PmcaSetGain(int gain);

int PmcaAsyncSetGain(int *result, int gain);

Defines gain (ADC). Gain should be a power of 2. If it is not, then it is rounded up to the nearest valid value. For example, 250 is rounded to 256 and 16,000 to 16,384.

input:	gain - must be between 129 and 16,384

return:	error code

Set time

C declaration:

int PmcaSetTime(char *time);

int PmcaAsyncSetTime(int *result, char *time);

Sets time in the time stamp

input:	time - time specified as character string HH:MM:SS

return:	error code

Set date

C declaration:

int PmcaSetDate(char *date);

int PmcaAsyncSetDate(int *result, char *char);

Sets date in the time stamp

input:	date - date specified as character string MM/DD/YYYY

return:	error code

Set lock

C declaration:

int PmcaSetLock(int code);

int PmcaAsyncSetLock(int *result, int code)

Sets the security lock.  If the code is zero, the protection is removed and all data is erased.

input:	code - must not be negative and smaller than 65,536

return:	error code

Set battery type

C declaration:

int PmcaSetBatteryType(PmcaBatteryType type);

int PmcaAsyncSetBatteryType(int *result, PmcaBatteryType type)

The specified main battery type is stored into the status data in PMCA

input:	type - battery type as defined in PmcaBatteryType

return:	error code

Set acquisition time

C declaration:

int PmcaSetAcquistionTime(int time);

int PmcaAsyncSetAcquisitionTime(int *result, int time)

Presets the acquisition time in seconds, live or real depending on the current timer mode

input:	time  - must be positive and less than 16,777,216

return:	error code

Set threshold

C declaration:

int PmcaSetThreshold (short threshold);

int PmcaAsyncSetThreshold(int *result, short threshold)

Sets the threshold

input:	threshold  - must not be negative and smaller than half of current gain

return:	error code

Developing PMCA Application Programs with Visual C++

The first step in developing PMCA application programs in Visual C++ is to create a project.  Include in the project the application source files.  Add PmcaCom.h header and if error codes are used for diagnostics also include PmcaErr.h.

There are two flavors of executable files that can be eventually generated: statically linked executable modules and modules utilizing the PMCA Dynamic Link Library (DLL).  In the first case, include PmcaLib.lib library file into the project.  In the second case, include PmcaDll.lib.

PMCA COM is a multithreaded software component and therefore the system must be configured to use multithreaded system libraries. This can be accomplished by appropriately setting Visual C++ options. On the "settings" dialog select "C/C++" tab, select "Code Generation" category and chose Multithreaded run-time library.

Developing PMCA Applications in Visual Basic

PMCA COM API functions can be easily imported into Visual Basic programs from PmcaDll.dll by declaring external functions in basic forms. The following lines illustrate declaration of  functions PmcaGetData and PmcaAsyncGetData:

Option Explicit

Private Declare Function  PmcaGetData _

Lib "PmcaDll.dll" (

ByRef buffer as Long, _

ByVal channel as Long, _

ByVal count as Long) as Long

Private Declare Function  PmcaAsyncGetData _

Lib "PmcaDll.dll" (

ByRef result as Long,

ByRef buffer as Long, _

ByVal channel as Long, _

ByVal count as Long) as Long

Both functions, PmcaGetData and PmcaAsyncGetData, can now be used as functions in Basic programs.

Lab Windows CVI:

NOTE: You cannot use the .lib file created in Microsoft Visual C/C++. You have to use/create a .lib that is compatible with LabWindows. Follow this procedure:

1. Add the header file PmcaCom.h to your project.

2. Open the header file.

3. Go to Options, then select Generate DLL import library.

4. Select PmcaDll.Dll

NOTE:  It is best to send commands with loops that retry sending the command if the first attempt fails.  This is especially necessary under battery operation.  See the Visual Basic and C++ examples provided.


Hardware Requirements

The ADMCA software is designed to run on Windows 98SE/ME/NT/2000/XP.  It will not run under previous versions of Windows such as 3.1 or the DOS operating system and will most likely not run efficiently on Win 95.  A minimum Pentium 100 MHz equivalent computer with 32 Megs of RAM, 800X600 screen resolution, and 256 colors is required.

For best performance:  Pentium 400 MHz equivalent computer or better with 64 Megs of RAM, 1024X768 screen resolution, and 24-bit color.

FP Quantitative Analysis Package requires  Pentium 400 MHz with 128 Megs of RAM.

A free USB port is required for DP4/PX4/DP5 communications.


Peak Calculations

Centroid / Peak Center P:

Normal:

The peak center, P, is calculated after subtracting the background as a weighted average of channels under the peak.

where Ci equals the counts in channel i after background subtraction is performed.

Median:

The channel with equal counts to the left and right of it is displayed.  This is often used for airborne particle sizing analyzers and aerosol research.

FWHM is calculated as the number of channels in which the counts exceed half of the maximum counts in the peak, with background subtraction corrected linearly for both edges of the peak.  When the smooth option is selected, the data in the ROI are first smoothed and then applied to the algorithm above.

Net Area S:

Uncertainty:

The Net Uncertainty (%) of the Peak defined by:

Net Rate:

The Net Rate is defined by the Net Area / Live_Time.

Gross Area, G:  Sum of total counts under the peak excluding the background points.

Example:  If background points = 1 and the ROI is three channels wide the Gross Area will be equal to only the center channel.  This is to remain consistent with the same boundaries that the Net Area uses in its calculation.

where

G	Gross area is the sum of counts under the marked peak
Bl	Background left is the area used to calculate the background left of peak center
Br	Background right is the area used to calculate the background right of peak center
n	Width of both background fields
N	Number of channels under the peak
Gaussian Centroid and FWHM Analysis

The centroid and FWHM of a peak can be calculated by fitting a Gaussian curve to the peak, and then using the centroid and FWHM of this Gaussian curve.  The advantage of this is that the Gaussian values will be closer to the true values when analyzing a small amount of statistics.  The following Gaussian equation is fit to the peak data using a least squares fit:

y(x) = counts in channel x

ó = standard deviation

x = channel number

x0 = centroid

background(b1,b2) = equation of background

The FWHM of the Gaussian curve is equal to 2.35ó.  Below is a plot of a Gaussian curve with an amplitude of 1, standard deviation of 1, and with no background.  The background is just a linear equation which is the same as for the regular analysis.

Variance FWHM Analysis

If the peak being analyzed is known to be Gaussian the FWHM of the curve can be calculated using the Variance Method.  The Variance Method uses the Normal Peak Centroid calculation as the mean ( [image]). The FWHM of the Gaussian curve is equal to 2.35 times the standard deviation (ó) which is the square root of the variance.

The mean [image] (peak center), is calculated after subtracting the background as a weighted average of channels under the peak.

where Ci equals the counts in channel i after background subtraction is performed.

The variance ( [image]) is calculated by subtracting the mean (Centroid channel) ( [image]) from the weight (channel i) which is then squared and multiplied by the corrected channel counts (Ci). Ci equals the counts in channel i after background subtraction is performed.  This is done for each channel i in the ROI and is then summed.  The resulting value is divided by the net area which is the sum of the corrected channel counts Ci.  The result is the variance which is the standard deviation squared.  The standard deviation is multiplied by 2.35 to get the FWHM.


MCA8000A Setup and Quick Start Guide

Load the software onto your computer.

First Time Use:

If you are using the software for the first time on a computer you must set the communication parameters if they differ from the default value of COM 1 and Baud Rate 115200.  Click to open the software and press Cancel when the ‘Starting Pmca’ dialog appears.  Go to the View menu and select Preferences.  This will open the ‘Review or Modify Preferences’ dialog.  Press the tab for the MCA page and set the Com Port and Baud Rate (115200 recommended).  Your computer is now ready to communicate with the MCA.

Quick Start Guide:

Open the Pmca software.  The Starting Pmca dialog will appear.

To open a file click on Open a File and see the Info and Select Pane sections below.

To Connect to the MCA8000A select Connect.  If the MCA is not on, the software will turn it on within 3 seconds and then connect (the MCA8000A will beep and the red light will go on).  The MCA is now connected and can respond to commands.  All the MCA acquisition parameters are in the ‘Set Acquisition Mode’ dialog.  This dialog is accessible  through its shortcut on the toolbar [image], from the MCA pulldown menu under Acquisition Setup, or by pressing F9  The dialog looks like this and conveniently sets all the acquisition parameters.

For more information about the specific functions see their Help section.  Here are a few quick hints to get started.

Set the Preset Mdoe to None.  This will cause the MCA to count up indefinitely.

Select the desired ADC Gain.  An ADC Gain of 1024 is most common.

Press OK.  Now press the Start / Stop button [image] on the toolbar.  The MCA is now taking data.  The info panel will indicate that the MCA8000A is acquiring.  You will see the screen updating with the spectrum.  To stop the acquisition, press the Start / Stop button [image] on the toolbar.  The info panel will indicate that the acquisition has stopped.  Keyboard hint:  the space bar starts and stops acquisitions.

Info Pane

The Info Pane displays the current status of the MCA as well as Peak Information if a Region of Interest (ROI) has been set.  To set an ROI click on the Edit ROI button [image] on the toolbar.  The mouse cursor has now changed to [image].  This is the Edit ROI cursor mode.  To set an ROI left-click and drag the mouse over the desired region.  An ROI has now been set.  Additional ROIs can now be set by the same left-click and drag.  To exit the Edit ROI cursor mode press the Edit ROI button on the toolbar.  The cursor has now changed back to the normal cursor.  The U and Y keys on the keyboard also mark ROIs.  Hold down the U key to mark an ROI to the right and the Y key to mark an ROI to the left.

Select Pane

The Select Pane displays cursor information (present channel location and counts in that channel), x and y-axis range settings, and the scale of the spectrum (linear, square root, and log).  At the right end of the Select Pane there are four arrows.  The up and down arrows are the same as the up and down arrows on the keyboard and change the y-axis range.  The left and right arrows change the x-axis range.

The left and right arrows on the keyboard move the cursor through the spectrum channel by channel.

Saving a Spectrum

To save a spectrum click on the File menu and select Save As.  Enter in the appropriate file name and press OK.

Plot Pane View (Sets the display colors and styles)

The Plot Pane View is accessible from the toolbar [image], or from the Display menu.  Until desired color schemes and styles are found it is recommended that all the check boxes be checked.

Modify Spectrum Properties:

The Modify Spectrum Properties dialog allows the user to change the file name, tag, description, and line contour style.  It is accessible from the toolbar [image] or from the File menu.


Main Spectrum display window.  Displays the data from the MCA and any other opened files.  See Spectrum Display.


DPP menu

View DPP menu

DPP | Open Start Dialog

Opens the start dialog.  The start dialog gives you the option to open a file or connect to a MCA8000A/DP4/PX4/DP5 when starting the program.  The application is configured to operate with the device type displayed in the dialog.

The following menu items are available for DP4/PX4/DP5 only:

DPP | DP4/PX4/DP5 Setup

Opens the DP4/PX4/DP5 Properties dialog. This dialog enables the user to set or review General, MCA, Shaping, Gain & Pole Zero, Power and Misc user definable properties for the DP4, PX4 and DP5.

DPP | Send Hardware Configuration (<toolbar> [image])

Sends the current configuration to a DP4/PX4/DP5.

DPP | Tune Slow/Fast Thresholds (<toolbar> [image])

Tunes both the slow and fast thresholds.  REMOVE THE SOURCE BEFORE RUNNING.

DPP | MCA/DELTA Mode (<toolbar> [image])

  Toggles between DP4/PX4/DP5 DELTA and MCA acquisition modes.

DPP | Display Settings (<toolbar> [image])

  Provides an configuration summary for the current file or DP4/PX4/DP5 device.  The current file or device is selected by the spectra list dialog.  The live spectrum displays the configuration of the current DP4/PX4/DP5.

PX4 Gain Controls

DPP | Multiplty Delta By 10 (<toolbar> [image])

Multiplies the gain increment by 10 times.

DPP | Divide Delta By 10 (<toolbar> [image])

Divides the gain increment by 10 times..

DPP | Decrement Gain By Delta (<toolbar> [image])

Decrements the gain by the selected gain delta.

DPP | Increment Gain By Delta (<toolbar> [image])

Increments the gain by the selected gain delta.


Toolbar

The toolbar is located directly beneath the file pulldown menus at the top of the window.  It can be displayed or hidden.  The toggle to display or hide the toolbar is in the  View menu.  If a check is next to Toolbar in the View menu, then the toolbar is currently displayed.  To hide the toolbar select Toolbar from the View menu.  When the toolbar is hidden there is no check next to Toolbar in the View menu.

The toolbar can be placed anywhere on the screen by clicking and dragging it from beneath the File menus.  If you are running at 600X480 screen resolution you may need to drag the toolbar from beneath the file menus in order to see all of the shortcut buttons.

The toolbar has shortcuts for the different functions of the MCA.  From left to right they are:

  Open:  Shortcut to the Open dialog box.

  Save:  Saves the active spectrum.

WARNING:  If you have taken data and saved it, then deleted data from the mca and taken new data and press this button, you will overwrite your previous file.  Use the Save As command under the File pulldown menu to enter in a new file name.

  Print:  Prints the spectrum display.

  Copy:  Copies the active spectrum to the clipboard.

  Modify:  Opens the Modify Spectrum Properties dialog box.

  Acquisition Setup:  Opens the Acquisition Setup dialog box.

    Connect / Disconnect:  Connects or disconnects the MCA8000A.

    Start / Stop:  Starts or stops acquisition of data.

  Delete Data and Reset Time:  Deletes the data and resets the timers in the current group of the mca.

  Plot View:  Opens the Plot Pane dialog box

  Show Spectra List:  Opens the Spectra List.

  Full Horizontal Range:  Sets the horizontal range to the maximum number of channels of the active spectrum.

  Autoscale Vertical Range:  Autoscales the vertical range to the maximum number of counts that exist in the spectrum.

  Select View:  Puts the cursor in Select View mode which sets a zoom box (see Select View).

  Center:  Brings the portion of the spectrum that the cursor is presently on to the center of the screen.  This is useful if the cursor has left the screen due to moving the horizontal scroll bar.

  Define ROI:  Opens the Define ROI dialog box.

  Edit ROI:  Puts the cursor in Edit / Mark ROI mode (see ROI).

    Enable / Disable Calibration:  Toggles the calibration on and off.

  Calibrate:  Opens the Calibrate dialog box.

  Peak Search:  Opens the Peak Search dialog box.

  Expression:  Opens the Define Expression dialog box.

  FP:  Opens the Fundamental Parameters Analysis Package if ordered.

  About:  Opens the About dialog which displays version and serial number information.

  Help:  Context sensitive help.  Move the question mark over the area that help is required and click.

Mini-X Toolbar Button

 Mini-X Controller:  Opens the Mini-X Controller Application if installed.

DP4/PX4/DP5 Toolbar Buttons

Additional DP4/PX4/DP5 toolbar buttons are provided to provide quick access to new DP4/PX4/DP5 functions.  These functions can also be selected with the DPP menu.

  Send Hardware Configuration:  Sends the current configuration to a DP4/PX4/DP5.

 Tune Slow/Fast Thresholds Tunes both the slow and fast thresholds.  REMOVE THE SOURCE BEFORE RUNNING.

  MCA/DELTA Mode:  Toggles between DP4/PX4/DP5 DELTA and MCA acquisition modes.

  Display Settings:  Provides an configuration summary for the current file or DP4/PX4/DP5 device.  The current file or device is selected by the spectra list dialog.  The live spectrum displays the configuration of the current DP4/PX4/DP5.

 Multiplty Delta By 10:  Multiplies the gain increment by 10 times.

 Divide Delta By 10:  Divides the gain increment by 10 times..

 Decrement Gain By Delta:  Decrements the gain by the selected gain delta.

 Increment Gain By Delta:  Increments the gain by the selected gain delta.

Hint for 800x600 Displays

Double click the toolbar to undock.  Adjust the gain.  Double click the toolbar to redock.


Status Bar

The status bar is located at the bottom of the program window.  It can be toggled on or off from the View menu.  A check next to Status Bar means the Status Bar is on.  No check means the Status Bar is off.

The Status Bar gives the user information about the MCA8000A software.  When the cursor is placed over a button, the Status Bar displays a description of the button.  On the right side of the Status Bar is information about the key modes of the computer.  The MCA8000A power status is indicated on the status bar.  When the MCA is on AC power a cord is shown and the pop-up label says AC Power.  When on batteries, a battery is shown and the pop-up displays the remaining life.

DP4/PX4/DP5 Status Bar Indicators

Additional indicators have been added to to display the status of DP4/PX4/DP5 devices.  On the left side is the number of USB devices detected.  On the right is the USB connected connected status of the DP4/PX4/DP5.  The green USB icon indicates the application is successfully communicating over the USB and can get valid status information.  The red icon indicates that the device is not communicating or that the last status information transfer was not correctly completed.

Status indicating no devices are connected or communicating.

Status indicating one USB device has been found and is communicating.


DP4/PX4 Properties
DP4/PX4/DP5 Properties

This window enables the user to set or review General, MCA, Shaping, Gain & Pole Zero, Power and Misc user definable properties for the DP4 and PX4.

General Tab

MCA Tab

Shaping Tab

Gain & Pole Zero Tab

Power Tab

Misc. Tab

At the bottom of the dialog there is a Defaults button.  This button quits the current

since the last Apply button press or configuration read.


DP4/PX4 Properties - General
DP4/PX4/DP5 Properties - General

General Tab:

Port:  Always set to USB.  ADMCA currently only supports USB capable DPPs.

USB Refresh (ms):  USB data refresh rate in milliseconds.  It is recommended that this value be set to approximately 1000 milliseconds or more.

Configuration Settings Status Text:  Displays the current status of configuration loads and saves.

Select New Configuration Settings

Read Amptek Detector Configuration:  Selects a default configuration from a list of configurations.

Recall Previous Software Configuration: Recalls the last configuration saved or applied.

Read Current Hardware Configuration: Reads the configuration settings stored in the attached DP4/PX4/DP5 hardware.

Open Predefined Configuration File: Opens and loads a configuration from a selected file.

Configuration Options

Save Current Configuration To File:  Saves the current configuration to a selected file.

Show Current Configuration: Displays the current configuration in a dialog.

Copy Configuration To Clipboard: Copies the current configuration to the clipboard.

Startup Configuration

Use Configuration Stored In Hardware (PX4 Only):  Uses the configuration stored in hardware at startup.  If no configuration is available then the last configuration saved is used.

Use Configuration Stored In Software (PX4 Only): Uses the last saved at startup.

Boot Flag Configuration (DP5 Only)

Power-Up Configuration

o	Boot unconfigured: In this mode, upon power-up, the DP5 will be in an unconfigured state. If present, the PC5 and detector will not be powered on until the first configuration packet is received. Also, the shaper, MCA, etc. are not configured.

o	Boot configured: Upon power-up, the DP5 will use the last configuration it received before it was powered off. It will turn on all supplies, including the PC5 HV & TEC supplies (if present, and if these were previously configured to be powered on). The DP5 will be ready to take data, once the detector has cooled.

Note: This setting requires the DP5 to be power-cycled to take effect.

RS232 Baud Rate

o	57,600: This primarily exists for backward compatibility with DP4/PX4/DP5 RS232 applications.

o	115,200: Recommended, for higher-speed transfers.

Note: This setting requires the DP5 to be power-cycled to take effect.

FPGA Clock

o	20MHz: Operating the DP5 at 20MHz consumes less power than 80MHz and allows longer peaking times (up to 102us), but limits throughput, minimum peaking time (0.8us), etc.

o	80MHz: This is the recommended clock rate for SDD detectors; it allows faster peaking times (min 0.2us) and higher throughput than 20MHz, but requires a bit more power.

Note: This setting is live and will take effect immediately.

Requested HV Polarity

The polarity of the HV supply on the PC5 is not under software control; it is configured in hardware, via jumpers set at the factory.  This software configuration setting tells the DP5 what polarity is required, and the DP5 will not allow the PC5 to turn on if its polarity doesn’t match the Boot Flag.

o	Negative: Amptek’s SDD detectors require negative HV.

o	Postive: All other Amptek detectors require positive HV.

Note: This setting requires the DP5 to be power-cycled to take effect.

Fast Channel Shaping

o	Normal: The fast channel peaking time is 400nS (for a 20MHz clock) or 100nS (at 80MHz).

o	4x Slower: The fast channel peaking time is 1.6uS (for a 20MHz clock) or 400nS (at 80MHz).

Note: This setting requires the DP5 to be power-cycled to take effect.

Spectrum Offset

o	None: No spectrum offset is applied, the spectrum zero is derived soley from BLR.

o	Use Offset: The Boot Option Spectrum Offset is added to BLR.  This shifts the spectrum left or right along the horizontal axis.  This permits channel zero to have zero energy.

Note: This setting is live and will take effect immediately.  To change the spectrum offset, set this option to Use Offset, click OK, then Set DP5 Boot Flags. Next, read the boot flags again by selecting the APPLY button. This will enable the Refresh Spectrum Offset button. Click the Refresh Spectrum Offset button to refresh the DP5 Spectrum Offset values.  For more infomation also see Setting a DP5 Spectrum Offset.

Peak Detect

o	Max only (normal operation): This is the correct setting for normal operation.

o	Max and min: This allows the peak detect (and MCA) to capture local minima of the shaped pulse stream, in addition to local maxima. This is useful for capturing the noise Gaussian for determining the true spectrum zero. (The slow threshold must be set very low to accomplish this.)

Note: This setting is live and will take effect immediately. It is also volatile, it will reset to ‘Max only’ the next time the DP5 is powered on.

MCA Channel

o	Slow channel (normal operation): This is the correct setting for normal operation.

o	Fast channel: This sets the source for the MCA to the fast channel, rather than the slow channel. The fast channel does not have BLR or a pole-zero, but this setting does allow some insight into the operation of the fast channel.

Note: This setting is live and will take effect immediately. It is also volatile, it will reset to Slow channel the next time the DP5 is powered on.

Setting a DP5 Spectrum Offset

NOTE: To set a DP5 Spectrum Offset, a DP5 type device must be connected and operational, also the Spectrum Offset boot flag must be set to Use Offset.

The Refresh Spectrum Offset button allows the spectrum offset status to be updated without having to close and then re-open the configuration dialog.

•	If the Spectrum Offsset boot flag is set to None pressing the Refresh Spectrum Offset button will disable the Spectrum Offset controls.

•	If the Spectrum Offsset boot flag is set to Use Offset pressing the Refresh Spectrum Offset button will enable the Spectrum Offset controls and update the Spectrum Offset control values.

The DP5 Spectrum Offset textbox sets the spectrum offset by percent full scale.  The DP5 Spectrum Offset is usually between -25.00 to 25.00 percent full scale.  The default value is 0.0%.

The Spectrum Offset value is also displayed in channels for reference.  Note that the Spectrum Offset can be in fractions of a channel.


DP4/PX4 Properties - MCA
DP4/PX4/DP5 Properties - MCA

MCA Tab:

Acquisition Mode: Selects the acquisition mode, either MultiChannel Analyzer (MCA)  or MultiChannel Scaler (MCS).  In MultiChannel Analyzer (MCA) each channel is connected to a counter, so the output of the MCA is an array of count values, one count value for each amplitude range or channel.  MCA is the normal mode of operation.  In a MultiChannel Scaler (MCS) each data channel corresponds to time instead of amplitude (energy), with the channel boundaries corresponding to start and stop times.  Each value in the array represents the total number of counts above the slow threshold during the appropriate time interval.

MCS Timebase: Sets the MCS time interval per channel.

MCA Channels: Sets the number of acquisition channels.  The DP4 and PX4 supports 256, 512, 1024, 2048, 4096 or 8192 channels.

Gate Input (TTL): Sets the TTL gate input source.  The TTL gate input includes or excludes events from the spectrum.

Preset Time (sec): Sets the preset duration of time requested for the current acquisition in seconds.  Values can be selected from the list or typed in.

(Also see Preset Count)

Slow Threshold

Percent: Selects a slow threshold setting by percent of the full energy scale.

Channel: Selects a slow threshold setting by the number of MCA channels selected.

Cursor: Selects a slow threshold setting by the current cursor position.

Tune Slow Threshold: Automatically tunes the slow channel threshold.  Please wait until the operation has completed before proceeding.

Gain Scale Thresholds Enabled (Label):  This label is visible only when Gain Scale Thresholds is enabled.

Gain Scale Thresholds Enabled (Checkbox):  Enables automatic scaling of the slow/fast thresholds as the gain is changed.

  Slow threshold controls including the Gain Scale Thresholds Enabled Label.  (See Setting the Slow Threshold)

Preset Count

Clear Count:  Clears the current preset count values including the low and high channels.

Current ROI:  Set the preset count low and high channel values to the current ROI.

Cursor:  Sets the preset count channel to be at the current cursor position.  The low channel value is set to one less than the current cursor postion and the high channel value is set to one greater than the current cursor position.

Low Channel:  Preset count low channel number.

High Channel:  Preset count high channel number..

Count: The preset number of counts requested in selected channel range. Channel values are stored in SCA(7).

Single-Channel Analyzer (SCA)

Select Single Channel Analyzer: Selects the current single channel analyzer.  The channel controls act on the currently selected SCA channel.

Channel Controls

Enable Channel:  Enables the currently selected SCA when checked.

Lower Level Threshold:  SCA lower level threshold.  Shaped output events above this channel (energy range) will generate a logic pulse at the corresponding output.

Upper Level Threshold: SCA upper level threshold.  Shaped output events below this channel (energy range) will generate a logic pulse at the corresponding output.

Update Preset Count:  Updates the preset count settings if SCA(7) channel controls have been changed.


DP4/PX4 Properties - Shaping
DP4/PX4/DP5 Properties - Shaping

Shaping Tab:

Pulse Shaping

Time to Peak: Sets the time to peak of the shaped pulse.  This value also equals the fall time of the shaped pulse.

FlatTop Width: Sets the duration of the shaped pulse trapezoidal flat top.

Pile-Up Rejection (PUR)

PUR Off/On: When set to on pile-up rejection (PUR) is enabled.

Fast Threshold: Sets the fast channel threshold, events with fast channel amplitude below this are rejected.

Tune Fast Threshold: Automatically tunes the fast channel threshold.  Please wait until the operation has completed before proceeding.  REMOVE THE SOURCE BEFORE RUNNING.

RTD Rules:

Events whose shaped slow channel amplitude is below the RTD slow threshold are kept.

 - OR -

Events whose fast channel amplitude is below the fast threshold are rejected.

- OR -

Events whose measured HWHM is wider than the RTD Time Threshold are rejected.

Gain Scale Thresholds Enabled (Label):  This label is visible only when Gain Scale Thresholds is enabled.

  Fast threshold controls including the Gain Scale Thresholds Enabled Label. (See Setting the Fast Threshold)

Rise Time Discrimination (RTD)

DP4/PX4 RTD Controls

RTD Off/On: Enables/disables RTD.

RTD (Slow) Threshold: If RTD is enabled, sets the RTD slow threshold.  This threshold applies to the slow channel.  Only events exceeding this threshold will be analyzed by the RTD circuit; all events below this threshold are accepted.

RTD Fast Threshold: If RTD is enabled, sets the HWHM for the fast channel.  Only events with a HWHM below this value will be accepted.

DP5 RTD Controls

RTD Off/On: Enables/disables RTD.

RTD Ratio: If RTD is enabled, compares the fast channel peak height to the slow channel peak height.  If this ratio is sufficiently high (fast risetime), the event is accepted.  If this ratio is low, the event is rejected.

RTD Slow Threshold: If RTD is enabled, sets the RTD slow threshold.  This threshold applies to the slow channel.  Only events exceeding this threshold will be analyzed by the RTD circuit; all events below this threshold are accepted.

Baseline Restoration (BLR) Notes:

The DP4 and PX4 have a baseline restorer, which can be used when baseline shifts due to count-rate changes, power supply drift, or if other detector effects need to be nulled.  All digital samples below the existing baseline are integrated. When the sum reaches a preset value, a baseline up correction is added to the baseline.  Countering this occasional upward correction is a baseline down correction.  Each correction has four settings, very slow, slow, medium and fast.

Baseline Restoration Quickset

Slow: Sets BLR to a suggested correction value for slow count rate.

Medium: Sets BLR to a suggested correction value for medium count rate.

Fast: Sets BLR to a suggested correction value for fast count rate.

Advanced Baseline Restoration (BLR)

AutoBaseline Up/Down Spin: Enumerates all the available BLR settings, recommended for advanced users only.

Down Correction: Sets the BLR down correction.

Up Correction: Sets the BLR up correction.

BLR: Enables/disables BLR.

Reset: Resets the AutoBaseline Up/Down Spin to BLR:ON DN:1 UP:1.

AutoBaseline: Enables/disables autobaseline.

AutoBaseline NOTE:

Auto-Baseline is intended to be used with reset-style preamps (i.e. the Amptek XR100CR). When the DP4/PX4/DP5 detects that reset has occurred, it temporarily disconnects the detector from the front-end electronics and averages the voltage offset produced by the front end. The detector is reconnected and the measured offset is used to correct the digital baseline.  Also, BLR and AutoBaseline should not be used at the same time.


DP4/PX4 Properties - Gain & Pole Zero
DP4/PX4/DP5 Properties - Gain & Pole Zero

Gain & Pole Zero Tab:

Gain

Coarse: Sets the coarse gain.

Fine: Sets the fine gain.

Enter Gain Value (PX4): Enter a gain value here to have the coarse and fine gain automatically calculated.  The coarse and fine gain settings are calculated and updated when the settings are applied.

Other Gain & Pole Zero Controls

Start/Stop Acquisition: Starts/stops data acquisition.

Vertical Scale: Adjusts the plot vertical scale.

Delete Data and Reset Time: Deletes the acquisition data and resets the acquisition time.

Pole Zero (PX4 Only): Pole zero adjust.

Input Offset (PX4 Only): Sets the input signal offset.

Tune Input Offset (PX4 Only): Automatically sets the input signal offset.  First a coarse input offset adjust is done, then a fine input offset is done to complete the input offset adjustment.

Input Polarity (PX4 Only): Determines if the PX4 front-end is inverting or not inverting. Positive = Front-end non-inverting, Negative = Front-end Inverting.

Detector Reset Lockout Period: Sets the duration of the lockout interval following a reset pulse from the preamplifier.


DP4/PX4 Properties - Power
DP4/PX4/DP5 Properties - Power

Power Tab:

Cooler Temperature (PX4/DP5)

Set Point Up/Down Spin and Edit: Enter a cooler temperature in Kelvin or use the spin control to adjust the value.  Click or press the enter key to calculate the closest actual setting.

TEC Temperature Monitor: Displays the TEC temperature in Kelvin when the monitor is running.

High Voltage Bias (PX4/DP5)

HV Enable: Enables/disables the detector high voltage.

HV Up/Down Spin and Edit: Enter a voltage or or use the spin control to adjust the value.  Click or press the enter key to calculate the closest actual setting.

High Voltage Monitor: Displays the detector high voltage when the monitor is running.

Board Temperature Monitor: Displays the current board temperature in Celsius when the monitor is running.

Monitors

START: Starts all available monitors running in the configuration dialog.

STOP: Stops all monitors running in the configuration dialog.

Preamp Voltage (PX4 Only): Selects the preamp power voltage (5 or 8.5 volts).


DP4/PX4 Properties - Misc.
DP4/PX4/DP5 Properties - Misc.

Misc. Tab:

Analog Out: Sets the analog output DAC output type.

Output Offset: Sets the output DAC offset.

Aux (PX4 Only): Selects the auxiliary output type.

Audible Counter (PX4 Only): Selects the audible counter volume setting.

Oscilloscope: Displays a digital oscilloscope. (See Oscilloscope topic).

PX4 Descriptor Text (PX4 Only)

Send PX4 Text: Stores a descriptor string in non-volitile memory.

Read PX4 Text: Reads a descriptor string from non-volitile memory.

Show updates dialog at startup.: Displays the Update DPP Notice Dialog at startup.


Start Dialog

The start dialog gives you the option to open a file or connect to a MCA8000A/DP4/PX4/DP5 when starting the program.  The application is configured to operate with the device type displayed in the dialog.  The start dialog can be opened at any time from the DPP menu.

Selecting the Device Type

Upon startup, the device type selected with the start dialog.  There are four device type options:

1.	MCA8000A

2.	DP4 / X123 / GammaRAD

3.	PX4

4.	DP5 / X123-SDD


DP4/PX4 Documentation
DP4/PX4/DP5 Documentation

Addition Information for DP4/PX4/DP5, X-123, X-123 SDD, GAMMA-RAD, and more.

Amptek Documentation

Amptek Home Page


DP4/PX4 Update DPP Notice Dialog
PX4 Update DPP Notice Dialog

The Update DPP Notice Dialog checks the connected PX4 device for FPGA and firmware revisions for compatibility with the ADMCA software.  If updates are necessary to run the current version of software, the dialog will be displayed with a version summary.

If the Update DPP Notice Dialog has been disabled, it can be enabled from the PX4 Properties - Misc Tab.

 Update DPP Notice Dialog


Note:  Keyboard commands will only work when the main spectrum display is the active window.  If the spectra list is open and active, the keyboard commands will not work.  All MCA8000A acquisition commands, such as start, stop, delete data, etc… only apply to the live date from the MCA.  If another spectrum is opened froma  file and the MCA is connected, the acquisition commands will still control the MCA.


DP4/PX4 Info Pane
DP4/PX4/DP5 Info Pane

The DP4/PX4/DP5 info pane displays status and ROI information for the active spectrum.  The Tag field displays the Tag of the spectrum.  To change the Tag of the active spectrum go to the File menu and select Modify.

The info pane displays the DP4/PX4/DP5 status information:

Device:  Identifies the type of DPP that is currently connected (DP4/PX4/DP5).  If the software has been used only to open files and has not connected to a DPP, it will display DP4, PX4, or DP5 depending upon the acquisition software startup configuration.  If a DP4/PX4/DP5 is connected, the serial number of the unit will also be displayed.

Tag:  Tag of the active spectrum.

Mode: MCA, DELTA, or Limited MCS

Channels:   Current number of acquisition channels.

LLD Thresh:  Current low level threshold as a percent of full energy scale.

Fast Thresh:  Current fast threshold setting.

Peak Time:  Time to peak setting.

Gain:  DP4/PX4/DP5 total gain setting.  This takes into account both the coarse and fine gain.

Gain Delta:  The gain can be incremented/decremented by this amount.  The gain delta is used to quickly and precisely adjust the gain (PX4).

Preset Mode: Displays the current Preset acquisition mode.

Preset:  The preset acquisition time or counts.

Accum Time: Displays the accumulation time counter.

Total Count: The total number of spectrum counts.  (See slow counts in the DP4/PX4/DP5 hardware manual.)

Input Count: The total number of counts input.  (See fast counts counts in the DP4/PX4/DP5 hardware manual.)

Total Rate: The total count rate, which is the input counts over accumulation time.

Dead Time:  The percentage of time that true events are assumed to have no effect upon the behavior of the detector.

Start Time:  Displays the start time and date stamp.

Status:  The current condition of the DP4/PX4/DP5 (acquiring, stopped, disconnected).

Below the status information is the peak information of the selected ROI.  The selected ROI is the ROI that the cursor is presently on.

The Peak Information section displays:

Centroid:  The Centroid position of the peak.

FWHM:  The Full Width at Half Maximum resolution.

Net Area:  The Net Area under the peak.

Uncertainty:  The Net Uncertainty of the Peak.

Net Rate:  The Net Counting Rate under the peak.

Gross Area:  The Gross Area under the peak.

Library Label:  If a library is loaded the label will appear here.

Click here to view the equations used to calculate the above.

Monitors:

Det. TEMP: Displays the TEC temperature in Kelvin.

Board Temp: Displays the current board temperature in Celsius.

Det. HV: Displays the detector high voltage.

To change the background color or font of the info pane go to the Display pulldown menu and select Info Pane and then either Font or Background.  Or, right click and select Info Pane and then Font or Background.

The info pane can be changed to any desired width.  Move the cursor onto the border of the info pane and spectrum display to see the “sizing” cursor.  Click and drag the border to the desired position.


DPP Dead Time Calculations

The Model

DPP dead time is calculated using a nonparalyzable model.  A fixed time (t) follows each true event during the live period of the detector.  If a true event occurs during a dead period, it is assumed to have no effect on the behavior of the detector.

The Calculations

n = true interaction rate = corrected fast count

m = recorded count rate = fast count

t = system dead time = post true event dead time

n = m / (1 - (m * t))	[nonparalyzable model]


DPP Monitors

Board Temperature

Board Temperature is the current temperature measured on the printed circuit board in Celsius degrees.

High Voltage (PX4 only)

High Voltage is the detector high voltage measured in volts.

Thermoelectric Cooler (PX4 only)

Thermoelectric Cooler is the detector temperature measured in Kelvin.


DPP Acquisition Modes

Multichannel Analyzer (MCA)

The Multichannel Analyzer (MCA) produces the energy spectrum. Its input is the peak amplitude of the shaped pulse (a digital value). Every time a pulse has a particular digitized amplitude, the value at the corresponding memory location is incremented. In effect, the memory acts as a set of independent counters, each covering a narrow range of energy. Counts are accumulated into these "bins" or "channels," producing a histogram of the counts. This histogram is the energy spectrum.

Delta/Total Count Mode (MCA:DELTA, MCS:DELTA)

In Delta mode, the spectrum only displays counts received in the most recent data update interval (i.e., 1 second). The histogram memory is cleared after each update. In Total mode, counts are integrated. Integration begins at the end of the update when Total was pressed and continuous until the update after Delta was pressed. Selecting Delta mode is used to clear the spectrum. (Note: the integration takes place in the DP4/PX4/DP5, not the host PC.)

Multichannel Scaler (MCS)

A Multichannel Scaler (MCS) is similar to an MCA but its channels refer to time instead of energy (or pulse amplitude). One starts data acquisition with a given counting time per channel (X to X sec in the DP4/PX4/DP5).  The system records the number of counts in the first interval and places them in the first channel, and so on.  The DP4/PX4/DP5 uses the slow (shaped) channel counts for MCS. If the peaking time is set to its fastest (0.8 ? s), then the MCS counts more closely resemble the input count rate. The MCS mode uses one of the SCAs, so this gives the user the capability of setting the upper and lower level thresholds.

Single Channel Analyzers (SCA)

The DP4/PX4/DP5 contains eight single channel analyzers (SCAs). Each SCA has an upper and a lower threshold. If an event occurs with a shaped output within the range defined by these thresholds, then a logic pulse is generated and is output to the Digital I/O connector, where it can be connected to external hardware.  The upper and lower limits of the 8 SCAs can be set independently in the software. SCA8 serves a dual purpose – not only does it operate like the other SCAs, but it is also used to set the Region-of-Interest (ROI) for the Preset Count mode of MCA operation. That is, when a Preset Count is selected, the MCA will stop after the programmed number of counts occurs in the SCA8 ROI.  (Also see the DP4/PX4/DP5 Properties MCA Tab.)


DPP MCA Control

Number of channels

The MCA can be set to have 256, 512, 1024, 2048, 4096, 8192(PX4 only) channels.

Slow Channel Threshold (LLD)

As with most MCAs, there is a low level discriminator on the slow channel. Only pulses exceeding this threshold will be recorded in the MCA spectrum. The register setting of 0-255 corresponds to about 0-25% of the full-scale output.

Gate

In software, the user may set the gate “off”, in which case the gate input is ignored. The user may also set it to active high or active low.

Presets

Many MCAs permit the user to stop data acquisition and to store the spectrum based on various predetermined conditions, such as real time, live time, total counts in the spectrum, counts in a predetermined channel, etc. The DP4 provides the total elapsed real time of data acquisition, so one could write embedded software to preset an interval and then to stop acquisition. The DP4 provides both fast and slow total counts, and it obviously provides counts in channels, so these can be easily used as presets. This would require software in the DP4 microcontroller, to read the time and counts and then to stop acquisition, along with interface software to set the preset values.


Quick DP4/PX4 Features Guide
DP4/PX4/DP5 Features

Auto Calibration (MCA8000A/DP4/PX4/DP5)

Setting Auto Calibration

Auto Calibration – Centroid Method

Auto Calibration – Cursor Method

Auto Calibration – 2 Peak Centroid Method

Setting Slow and Fast Thresholds (DP4/PX4/DP5)

Setting the Slow Threshold

Setting the Fast Threshold

Manually Setting the Slow and Fast Thresholds

Set Thresholds for Current Gain

Digital Oscilloscope


Auto Calibration (MCA8000A/DP4/PX4)
Auto Calibration (MCA8000A/DP4/PX4/DP5)

Setting Auto Calibration

Centroid Method  -  Calibrate from a single ROI centroid.

Cursor Method  -  Calibrate from the current cursor position.

2 Peak Centroid Method  -  Calibrate from 2 ROI centroids.

The Calibration dialog sets the options for the auto two point calibration settings.  The Auto Calibration section sets the calibration units and value as well as the auto calibration method.  In the Units field enter in whatever label is desired for the calibration.  This label appears in the Select Pane.  The default is keV.  It is most useful to enter in the units of the calibration.  In the Value field enter in the peak energy of the calibration source.  The default source is Fe55 which is 5.9 (keV).  In the Peak 2 Value field enter in the second peak energy of the calibration source.  The default source is Fe55, so the second peak defaults to 6.5 (keV).  The Method selection determines how the calibration channel is selected.  Centroid calculates the position of the calibration channel from the centroid of the region of interest.  Cursor sets the position of the calibration channel to the current cursor position.  2 Peak Centroid calculates the position of the calibration channel from the centroid of the region of interest of two peaks.

  Calibration dialog with Auto Calibration.

Toolbar shortcut:

Auto Calibration – Centroid Method

1. Select the source peak region of interest.

2. Click on the region of interest so it is active.

3. Press <Ctrl> + F5 to run the auto calibration.

Auto Calibration – Cursor Method

1. Select the source peak region of interest.

2. Click on the region of interest so it is active.

3. Position the cursor on the calibration channel.

4. Press <Ctrl> + F5 to run the auto calibration.

Auto Calibration – 2 Peak Centroid Method

1. Select the two source peak regions of interest.

2. Click on the largest region of interest so it is active.

3. Press <Ctrl> + F5 to run the auto calibration.


Auto Thresholds (PX4/DP4)
Setting Thresholds (DP4/PX4/DP5)

Setting the Slow Threshold

Percent:  Selects a slow threshold setting by percent of the full energy scale.

Channel: Selects a slow threshold setting by the number of MCA channels selected.

Cursor:  Selects a slow threshold setting by the current cursor position.

Tune Slow Threshold: Automatically tunes the slow channel threshold.  Please wait until the operation has completed before proceeding.

REMOVE THE SOURCE BEFORE RUNNING.

Press Tune Slow Threshold button.

The dialog may not be visible for a second.

Wait for the dialog box to return.

The old slow threshold is replaced with the new value.

Tune Slow Threshold only takes a few seconds to run.

Gain Scale Thresholds Enabled (Label):  This label is visible only when Gain Scale Thresholds is enabled.

Gain Scale Thresholds Enabled (Checkbox):  Enables automatic scaling of the slow/fast thresholds as the gain is changed.

Also see Setting Thresholds for the Current Gain.

  Slow threshold controls on the MCA Properties page.  See MCA Tab

Setting the Fast Threshold

Fast Threshold: Sets the fast channel threshold, events with fast channel amplitude below this are rejected.

Tune Fast Threshold: Automatically tunes the fast channel threshold.  Please wait until the operation has completed before proceeding.

REMOVE THE SOURCE BEFORE RUNNING.

Press Tune Fast Threshold button.

The dialog may not be visible for a second.

Wait for the dialog box to return.

The old fast threshold is replaced with the new value.

Tune Fast Threshold only takes a few seconds to run.

Gain Scale Thresholds Enabled (Label):  This label is visible only when Gain Scale Thresholds is enabled.

  Fast threshold controls on the Shaping Properties page.  See Shaping Tab

Manually Setting the Slow and Fast Thresholds

Setting the fast and slow thresholds is an important setup consideration.  Following is a step-by-step guide to correctly setting the fast and slow thresholds.

Configure the DPP and the application software for an acquisition.

Start an acquisition.

Remove the source.

Set to delta mode.

Setting the slow threshold:

1.	Look for counts on low end.

2.	Place cursor above low end counts.

3.	Open configuration dialog.

4.	Go to MCA tab.

5.	Press slow threshold cursor button.

6.	Press apply.

Setting the fast threshold:

1.	Open configuration dialog.

2.	Go to Shaping Tab

3.	Select a fast threshold.

4.	Press apply.

5.	Check Fast Count value in Info Panel.

6.	Repeat Steps C-E until the Input Counts value is approximately 5.

The thresholds are now set.  You are ready to begin an acquisition.

Replace the source.

Start an acquisition.

Setting Thresholds for the Current Gain

The slow and fast thresholds can be automatically set.  The Tune Slow/Fast Thresholds toolbar shortcut and menu item tunes both the slow and fast threshold.

Setting thresholds for the current gain takes only a few seconds. The application and DPP must be setup before running this procedure.

1. Verify the system is acquiring then remove the source.

2. Set the Upper Count Filter checkbox to checked.

3. Wait until the tuning procedure is done.

The slow and fast thresholds can also be automatically scaled as the gain is changed.  A checkbox on the DP4/PX4/DP5 MCA Properties Page must be set to automatically scale the thresholds as the gain is changed.  (Also see Setting the Slow Threshold)

Tune Fast/Slow Thresholds Menu Item:

Toolbar shortcut:

Setting thresholds for the current gain usually only takes a few seconds.

Another fast method of setting the slow threshold is the Tune Slow Threshold button.  (See Setting the Slow Threshold)

Another fast method of setting the fast threshold is the Tune Fast Threshold button.  (See Setting the Fast Threshold)


Setting Input Offset (PX4)

The input offset controls are on the Gain & Pole Zero Tab:.  Input offset controls are disabled for the DP4.

The input offset is set three ways:

1.	A value is set using the DP4/PX4/DP5 Properties controls.

2.	The Tune Input Offset button has been pressed.

3.	When the coarse gain is changed, the input offset is automatically tuned.

Input Offset (PX4 Only): Sets the input signal offset.

Tune Input Offset (PX4 Only): Automatically sets the input signal offset.  First a coarse input offset adjust is done, then a fine input offset is done to complete the input offset adjustment.

  Input Offset Controls


Digital Oscilloscope
Digital Oscilloscope (DP4/PX4/DP5)

The digital oscilloscope is selected from the DP4/PX4/DP5 Properties Misc. Tab.  Provides digital capture of input and output signals, reducing the need for an oscilloscope during initial setup and configuration.

1. Display 2. Channel Input from Analog Out 3. Clear Trace 4. Refresh Oscilloscope 5. Capture Trace 6. Timebase Measurement Display 7. Minimize Window 8. Close (Exit) Oscilloscope 9. Hide Oscilloscope Controls 10. Minimize Window	11. Show Oscilloscope Controls 12. Input Offset Adjust 13. Output Offset Adjust 14. Trigger Source from Aux Out 15. Trigger Position 16. Trigger Slope 17. Auto ReArm 18. Trace Persistence 19. Arm Trigger


PX4 Setup and Quick Start Guide

The PX4 Quick Start Guide

The PX4 Quick Start Guide provides the latest PX4 installation and software setup information.  Please read the PX4 Quick Start Guide before attempting to operate the PX4 for the first time.

View the PX4 Front Panel and the PX4 Back Panel.


X-123 Uses DP4 Setup README

ADMCA setup and operation is the same for the X-123 and DP4

NOTE: ADMCA setup and operation is the same for the X-123 and DP4.  Refer to the DP4 setup and operational information unless otherwise noted.

        The Amptek X-123 is a combination of other Amptek products.  The x-ray detector and preamplifier are the same as the XR100CR.  The digital pulse processor is the DP4, and the power supply board is the PC4-3. Please refer to the user manuals and specifications of those products for more complete information.


X-123 SDD Uses DP5 Setup README

ADMCA setup and operation is the same for the X-123 SDD and DP5

Please refer to the user manuals and specifications of those products for more complete information.


X-123 SDD, PX4/DP5 With XR-100SDD Setup README

High Voltage Polarity for Silicon Drift Detector (SDD) Devices

Amptek’s SDD detectors require negative high voltage.  All other Amptek detectors require positive high voltage.  If you have a PX4 with a XR-100SDD the high voltage is always correctly set (to negative). If you have a X-123 SDD or a DP5 with a XR-100SDD then the Requested HV Polarity Boot Flag must be Negative.  If the setting is wrong a Check Polarity Info Panel Message will be displayed.

Setting the High Voltage Polarity (X-123 SDD, DP5 With XR-100SDD)

In the General Tab, set the Requested HV Polarity Boot Flag to Negative. This setting requires the X-123 SDD or DP5 to be power-cycled to take effect.

Check Polarity Info Panel Message (DP5 / X-123 SDD)

This message indicates that the DP5 / X-123 SDD high voltage polarity is not correctly set, preventing the device from operating correctly.

X-123 SDD, PX4/DP5 With XR-100SDD High Voltage Monitor

In the Power Tab and in the DP4/PX4/DP5 info pane the high voltage monitor value displays as a negative value if the high voltage polarity is negative.  The high voltage bias setting is always as positive.

Please refer to the user manuals and specifications of those products for more complete information.


Check Polarity Info Panel Message (DP5 / X-123 SDD)

This message indicates that the DP5 / X-123 SDD high voltage polarity is not correctly set preventing the device from operating correctly.

Correctly Setting the High Voltage Polarity

In the General Tab, set the Requested HV Polarity Boot Flag to Negative for Amptek Silicon Drift Detector (SDD) Devices. Set the Requested HV Polarity Boot Flag to Positive otherwise. This setting requires the X-123 SDD or DP5 to be power-cycled to take effect.

Please refer to the user manuals and specifications of those products for more complete information.