XIA microDXP Product manual

microDXP
Technical Reference Manual
Version 3.15
October 7, 2019
microDXP Hardware Revision: H (8)
ProSpect Software
Software Revision: 1.0.24
XIA LLC
31057 Genstar Rd
Hayward, CA 94544 USA
Email: [email protected]
Tel: [phone]; Fax: [phone]
http://www.xia.com/
Information furnished by XIA LLC is believed to be accurate and reliable. However, no responsibility is assumed by
XIA for its use, or for any infringements of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of XIA. XIA reserves the right to
change hardware or software specifications at any time without notice.

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Table of Contents
Safety.............................................................................................................................................. 7
Specific Precautions..................................................................................................................................7
Power Source........................................................................................................................................7
Detector and Preamplifier Damage.......................................................................................................7
Servicing and Cleaning.........................................................................................................................7
Warranty Statement..................................................................................................................... 8
Contact Information:.................................................................................................................................8
Manual Conventions..................................................................................................................... 9
1Introduction ......................................................................................................................... 10
1.1 Features.......................................................................................................................................10
1.1.1 General Spectrometer Features...........................................................................................10
1.1.2 Embedded Systems Features...............................................................................................11
1.1.3 Custom OEM Features........................................................................................................11
1.2 Hardware Requirements..............................................................................................................11
1.2.1 Host Computer....................................................................................................................11
1.2.2 Detector/Preamplifier..........................................................................................................11
1.2.3 Power Requirements...........................................................................................................12
1.2.4 Operating Environment.......................................................................................................12
1.2.5 Regulatory Compliance.......................................................................................................12
1.3 Hardware Options.......................................................................................................................12
1.3.1 Communications and Power Interface................................................................................12
1.3.2 Analog Input .......................................................................................................................13
1.3.3 Power Supplies....................................................................................................................13
1.3.4 Pipeline Clock Speed Choice..............................................................................................14
1.3.5 Gain and Calibration Options .............................................................................................14
1.4 Firmware Options .......................................................................................................................14
1.4.1 Preamplifier Type ...............................................................................................................14
1.4.2 Custom Firmware................................................................................................................15
1.5 Application Examples.................................................................................................................15
1.5.1 Example 1. General-Purpose USB Spectrometer with MicroComU Companion Board....15
1.5.2 Example 2. General-Purpose Spectrometer Using RS232 and Custom Breakout Board ...16
1.5.3 Example 3. Dedicated Spectrometer Using RS232.............................................................16

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1.6 Software Overview .....................................................................................................................18
1.6.1 User Interface, e.g. ProSpect...............................................................................................18
1.6.2 Device Drivers, e.g. Handel................................................................................................18
1.6.3 Firmware.............................................................................................................................19
1.7 Support........................................................................................................................................19
1.7.1 Software and Firmware Updates.........................................................................................19
1.7.2 XUP Utility and Firmware Updates....................................................................................19
1.7.3 Related Documentation.......................................................................................................19
1.7.4 Email and Phone Support....................................................................................................20
1.7.4.1 Submitting a problem report:..........................................................................................20
1.7.5 Feedback.............................................................................................................................21
1.7.5.1 Export File Formats ........................................................................................................21
2Using the microDXP............................................................................................................ 22
2.1 Hardware Settings.......................................................................................................................22
2.1.1 Preamplifier Type Selection................................................................................................22
2.1.2 Input Signal Attenuation.....................................................................................................22
2.2 Board State and Configuration....................................................................................................23
2.2.1 Board Information and Status.............................................................................................23
2.2.1.1 ADC Sampling Rate / DSP Clock Speed: DSPSPEED ..................................................23
2.2.1.2 Gain Mode ......................................................................................................................23
2.2.2 Serial Number.....................................................................................................................24
2.2.3 On-Board Temperature.......................................................................................................24
2.3 Global Settings and the GLOBSET............................................................................................24
2.3.1 Preamplifier Settings...........................................................................................................24
2.3.1.1 Preamplifier Type ...........................................................................................................24
2.3.1.2 Decay Time: TAURC .....................................................................................................25
2.3.1.3 Reset Interval: RESETINT .............................................................................................25
2.3.1.4 Preamplifier Signal Polarity............................................................................................25
2.3.2 Advanced Processor Settings..............................................................................................25
2.4 MCA Settings and GENSETs.....................................................................................................26
2.4.1 Selecting the GENSET........................................................................................................26
2.4.2 MCA Size and Bin Width...................................................................................................26
2.4.3 Base Gain, Switched Gain and Digital Base Gain..............................................................27

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2.4.4 Reading the Current GENSET............................................................................................28
2.4.5 Saving the Current GENSET to Non-Volatile Memory .....................................................28
2.5 Spectrometer Settings and PARSETs .........................................................................................28
2.5.1 Selecting a PARSET...........................................................................................................28
2.5.2 Thresholds...........................................................................................................................28
2.5.3 Baseline Average Length....................................................................................................29
2.5.4 Fine Gain Trim....................................................................................................................29
2.5.5 Advanced Filter Settings.....................................................................................................30
2.5.6 Reading the Current PARSET ............................................................................................30
2.5.7 Saving the Current PARSET to Non-Volatile Memory......................................................30
2.6 Repetitive Configuration of Identical Systems...........................................................................30
2.6.1 Create Master Parameter Set…...........................................................................................30
2.6.2 Download a Master Parameter Set…..................................................................................30
2.7 Data Acquisition .........................................................................................................................30
2.7.1 Starting a Run .....................................................................................................................31
2.7.2 Stopping a Run....................................................................................................................31
2.7.3 Reading a Spectrum............................................................................................................31
2.7.4 Reading (and Calculating) the Run Statistics......................................................................31
2.7.5 Specifying fixed run lengths...............................................................................................32
2.8 Diagnostic Tools.........................................................................................................................32
2.8.1 Diagnostic Trace.................................................................................................................32
2.8.1.1 Trace Type (TRACETYPE)............................................................................................33
2.8.1.2 Sampling Interval (TRACEWAIT).................................................................................33
2.8.1.3 Trigger Type (TRACETRIG) .........................................................................................34
2.8.1.4 Pre-Trigger Position (TRACEPRETRIG).......................................................................34
2.8.2 Baseline Histogram.............................................................................................................35
2.8.3 DSP Parameters...................................................................................................................35
3MicroDXP Functional Description .................................................................................... 36
3.1 Organizational Overview............................................................................................................36
3.2 The Analog Signal Conditioner (ASC).......................................................................................36
3.2.1 Dynamic Range Reduction .................................................................................................37
3.2.1.1 Reset-Type Preamplifiers................................................................................................37
3.2.1.2 RC-Feedback Preamplifiers............................................................................................38

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3.2.2 Analog Gain........................................................................................................................39
3.2.2.1 Nominal Gain..................................................................................................................40
3.2.2.2 Switched Gain.................................................................................................................40
3.2.3 Nyquist Criterion.................................................................................................................41
3.3 The Analog to Digital Converter (ADC) ....................................................................................41
3.4 The Filter, Pulse Detector, & Pile-up Inspector (FiPPI).............................................................41
3.4.1 Clock Speed and Peaking Time Range...............................................................................41
3.4.2 FiPPI Variants.....................................................................................................................42
3.4.3 Digital Gain.........................................................................................................................42
3.4.3.1 Digital Base Gain............................................................................................................42
3.4.3.2 MCA Bin Width..............................................................................................................43
3.4.3.3 Fine Gain Trim................................................................................................................43
3.5 The Digital Signal Processor (DSP.............................................................................................43
3.5.1 Parallel Flash EEPROM......................................................................................................44
3.5.2 Serial Port (SPORT)............................................................................................................44
3.5.3 DMA Port............................................................................................................................44
3.5.4 DSP Code Variants .............................................................................................................44
3.6 PIC Microcontroller....................................................................................................................44
3.6.1 RS-232 Serial Port ..............................................................................................................45
3.6.2 I2C Serial Bus.....................................................................................................................45
3.6.3 I2C EEPROM .....................................................................................................................45
3.6.4 I2C Temperature Sensor .....................................................................................................45
3.6.5 PIC Code Variants ..............................................................................................................45
3.7 Interface to Host Computer.........................................................................................................45
3.7.1 On-Board mini-USB 2.0 .....................................................................................................45
3.7.2 Flex Cable Interface............................................................................................................45
3.7.3 Board-to-Board Interface....................................................................................................46
4Digital Filtering: Theory of Operation and Implementation Methods .......................... 47
4.1 X-ray Detection and Preamplifier Operation..............................................................................47
4.1.1 Reset-Type Preamplifiers....................................................................................................47
4.1.2 RC-Type Preamplifiers.......................................................................................................49
4.2 X-ray Energy Measurement & Noise Filtering...........................................................................49
4.3 Trapezoidal Filtering in the DXP................................................................................................51
4.4 Baseline Issues............................................................................................................................53

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4.4.1 The Need for Baseline Averaging.......................................................................................53
4.4.2 Raw Baseline Measurement................................................................................................54
4.4.3 Baseline Averaging in the DXP..........................................................................................54
4.5 X-ray Detection & Setting Thresholds........................................................................................55
4.6 Peak Capture Methods................................................................................................................56
4.6.1 The Slow Filter Gap Length................................................................................................56
4.6.2 Peak Sampling vs. Peak Sensing.........................................................................................57
4.7 Pile-up Inspection .......................................................................................................................58
4.7.1 Slow Pileup.........................................................................................................................59
4.7.2 Fast Pileup...........................................................................................................................60
4.8 Input Count Rate (ICR) and Output Count Rate (OCR).............................................................61
4.9 Throughput..................................................................................................................................61
Appendices................................................................................................................................... 63
Appendix A. MicroDXP Hardware Specification..................................................................................63
A.1 Board Dimensions and Mounting ................................................................................................63
A.2 Preamplifier Type Selector Switch ..............................................................................................63
A.3 Input Signal Attenuation..............................................................................................................63
A.4 Connector Locations and Pinouts.................................................................................................63
A.5 Power Supplies.............................................................................................................................68
Appendix B. GLOBSET Specification...................................................................................................68
Appendix C. GENSET Specification......................................................................................................69
Appendix D. PARSET Specification......................................................................................................70
Appendix E. RS-232 Communications...................................................................................................71

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Safety
Please take a moment to review these safety precautions. They are provided both for your
protection andto prevent damage to the microDXP module and connected equipment. This
safety information applies to all operators and service personnel.
Specific Precautions
Please take a moment to review these safety precautions. They are provided to prevent
damage to the microDXP and microCOMU printed circuit boards and connected
equipment. This safety information applies to all operators and service personnel.
Power Source
The microDXP USB Rapid Development Kit includes a wall-mounted power supply
intended to operate from an AC power supply in the 100VAC to 240VAC range at 50Hz
or 60Hz. Use of this development kit with AC voltage outside these specifications could
damage the unit and nullify the product warranty. Refer to Chapter 2 of this manual for
instructions on installing the power supply.
Detector and Preamplifier Damage
Because the microDXP does not provide power for the detector or preamplifier there is
little risk of damage to either resulting from the microDXP itself. Nonetheless, please
review all instructions and safety precautions provided with these components before
powering a connected system.
Servicing and Cleaning
To avoid personal injury, and/or damage to the microDXP and microCOMU boards or
connected equipment, do not attempt to repair or clean these units. These boards are
warranted against all defects for one (1) year. Please contact the factory or your distributor
before returning items for service.

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Warranty Statement
XIA LLC warrants that this product will be free from defects in materials and workmanship
for a period of one (1) year fromthe date of shipment. If any such product proves defective
during this warranty period, XIA LLC, at its option, will either repair the defective products
without charge for parts and labor, or will provide a replacement in exchange for the
defective product.
In order to obtain service underthis warranty, Customer must notify XIA LLC of the defect
before the expiration of the warranty period and make suitable arrangements for the
performance of the service.
This warranty shall not apply to any defect, failure or damage caused by improper uses or
inadequate care. XIA LLC shall not be obligated to furnish service under this warranty a)
to repair damage resulting from attempts by personnel other than XIA LLC representatives
to repair or service the product; or b) to repair damage resulting from improper use or
connection to incompatible equipment.
THIS WARRANTY IS GIVEN BY XIA LLC WITH RESPECT TO THIS PRODUCT IN
LIEU OF ANY OTHER WARRANTIES, EXPRESSED OR IMPLIED. XIA LLC AND
ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF
MERCHANTABILITYOR FITNESS FOR A PARTICULAR PURPOSE. XIA’S
RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE
SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH
OF THIS WARRANTY. XIA LLC AND ITS VENDORS WILL NOT BE LIABLE FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
IRRESPECTIVE OF WHETHER XIA LLC OR THE VENDOR HAS ADVANCE
NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
Contact Information:
XIA LLC
31057 Genstar Rd.
Hayward, CA 94544 USA
Telephone: [phone]
Downloads: http://support.xia.com
Email Support: [email protected]

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Manual Conventions
The following conventions are used throughout this manual
Convention
Description
Example
»
The » symbol leads you
through nested menu items
and dialog box options.
The sequence
File»Page Setup»Options directs you to pull
down the File menu, select the Page Setup
item, and choose Options from the sub menu.
Bold
Bold text denotes items that
you must select or click on in
the software, such as menu
items, and dialog box options.
...click on the MCA tab.
[Bold]
Bold text within [ ] denotes a
command button.
[Start Run] indicates the command button
labeled Start Run.
monospace
Items in this font denote text
or characters that you enter
from the keyboard, sections
of code, file contents, and
syntax examples.
Setup.exe refers to a file called “setup.exe”
on the host computer.
Italics
Italic text denotes a new term
being introduced , or simply
emphasis
peaking time refers to the length of the slow
filter.
...it is important first to set the energy filter Gap
so that SLOWGAP to at least one unit greater
than the preamplifier rise time...
<Key>
<Shift-Alt-
Delete> or
<Ctrl+D>
Angle brackets denote a key
on the keyboard (not case
sensitive).
A hyphen or plus between
two or more key names
denotes that the keys should
be pressed simultaneously
(not case sensitive).
<W> indicates the W key
<Ctrl+W> represents holding the control key
while pressing the W key on the keyboard
Bold italic
Warnings and cautionary text.
CAUTION: Improper connections or settings
can result in damage to system components.
CAPITALS
CAPITALS denote DSP
parameter names
SLOWLEN is the length of the slow energy
filter

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1 Introduction
The Micro Digital X-ray Processor (microDXP) is a high rate, digitally-based, multi-
channel analysis spectrometer designed for energy dispersive x-ray or gamma-ray
measurements in benchtop, networked, portable and embedded systems. Its versatile
analog front-end accommodates most solid-state and gas detectors and a wide range of
common preamplifiers, including pulsed optical reset, transistor reset, and resistive
feedback types. The microDXP offers complete computer control over all available
amplifier and spectrometer controls including gain (if applicable), filter peaking time, and
pileup inspection criteria. As with all DXP instruments, the firmware (i.e. DSP,
Microcontroller and FPGA code) can be upgraded in the field. Unlike other instruments in
the DXP family, microDXP firmware and parameters are stored locally in non-volatile
memory.
The architecture supports custom auxiliary digital access including the industry-standard
I2C serial bus and four configurable digital I/O lines. The microDXP is thus a flexible,
cost-effective OEM component that can form the core of a broad range of systems, from
basic XRF to the most demanding process and control applications emerging in research
and industry.
This version of the manual describes the new ‘blue’ microDXP pictured on the right below.
If your microDXP is green, as pictured on the left, please refer to the older version 1.0.2 of
this manual.
Figure 1-1: The new microDXP pictured on the right was released in 2015.
1.1 Features
The microDXP offers a set of standard and customizable features intended to address the
design requirements of a wide range of complex spectroscopy data acquisition systems.
1.1.1 General Spectrometer Features
Extremely compact unit replaces spectroscopy amplifier, shaping amplifier and
multi-channel analyzer (MCA) at significantly reduced cost and power consumption.
Operates with a wide variety of x-ray or gamma-ray detectors using preamplifiers of
pulsed optical reset, transistor reset or resistor feedback types.