VXI SVM2608 User Manual
SVM2608
4-Channel, 100 kSamples/s
Analog-to-Digital Converter
SER’S MANUAL
U
P/N: 82-0066-000
Released February 23, 2007
VXI Technology, Inc.
2031 Main Street
Irvine, CA 92614-6509
(949) 955-1894
VXI Technology, Inc.
2
www.vxitech.com
TABLE OF CONTENTS
INTRODUCTION
TABLE OF CONTENTS................................................................................................................................................3
Certification..........................................................................................................................................................5
Warranty ...............................................................................................................................................................5
Limitation of Warranty.........................................................................................................................................5
Restricted Rights Legend......................................................................................................................................5
DECLARATION OF CONFORMITY ...............................................................................................................................6
GENERAL SAFETY INSTRUCTIONS............................................................................................................................. 7
Terms and Symbols ..............................................................................................................................................7
Warnings...............................................................................................................................................................7
SUPPORT RESOURCES ...............................................................................................................................................9
SECTION 1.................................................................................................................................................................. 11
INTRODUCTION ....................................................................................................................................................... 11
Introduction ........................................................................................................................................................11
Overview ............................................................................................................................................................11
Acquiring Data ..............................................................................................................................................13
Triggering......................................................................................................................................................13
Linear Mode ..................................................................................................................................................14
Pre-Trigger .................................................................................................................................................... 14
Delayed Trigger.............................................................................................................................................14
FIFO Mode.................................................................................................................................................... 15
Calibrations ...................................................................................................................................................15
Test Bus.........................................................................................................................................................15
Commands.....................................................................................................................................................15
Option -01 .....................................................................................................................................................16
Physical Description...........................................................................................................................................18
Front Panel Interface Wiring ..............................................................................................................................19
SVM2608 Specifications ....................................................................................................................................20
SECTION 2.................................................................................................................................................................. 23
PREPARATION FOR USE...........................................................................................................................................23
Introduction ........................................................................................................................................................23
Calculating System Power and Cooling Requirements ......................................................................................23
Setting the Chassis Backplane Jumpers.............................................................................................................. 23
Setting the Base Address ....................................................................................................................................24
Example 1......................................................................................................................................................25
Example 2......................................................................................................................................................26
Module Installation/Removal .............................................................................................................................26
SECTION 3.................................................................................................................................................................. 27
PROGRAMMING....................................................................................................................................................... 27
Introduction ........................................................................................................................................................27
Device Memory Maps ........................................................................................................................................27
Function Offset..............................................................................................................................................27
Register Offset...............................................................................................................................................27
Data(Byte) Ordering ...........................................................................................................................................30
Determining the Register Address......................................................................................................................31
Accessing the Registers ...................................................................................................................................... 32
Description of Registers .....................................................................................................................................32
Microprocessor Commands................................................................................................................................41
SVM2608 Preface 3
VXI Technology, Inc.
Measurement Commands..............................................................................................................................41
Captured Data Calculations........................................................................................................................... 42
Resistance Measurement – Offset Method.................................................................................................... 43
Resistance Measurement – Dynamic Method ...............................................................................................43
Self Test Command.......................................................................................................................................43
Preset Setting Measurement Commands .......................................................................................................44
Calibration Commands..................................................................................................................................45
Error Processing ............................................................................................................................................47
Diagnostic Commands ..................................................................................................................................49
Examples ............................................................................................................................................................51
Example 1: Setting the Channel 2 and 4 Sample Rate to 123 ms (8.13 kHz)................................................51
Example 2: Setting Channel 2 to Acquire 200,000 Samples.........................................................................51
Example 3: Setting Channel 2 to Pre-acquire 100,000 Samples ...................................................................52
Example 4: Setting Channel 2 to Delay Acquisition by 1,500,000 Samples.................................................52
Example 5: Setting Channel 2 and 4 Timeout Register to Timeout after 2.5 s .............................................53
APPENDIX A...............................................................................................................................................................55
APPENDIX A ...........................................................................................................................................................55
Data Swapping Example.....................................................................................................................................55
INDEX......................................................................................................................................................................... 57
4 SVM2608 Preface
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CERTIFICATION
VXI Technology, Inc. (VTI) certifies that this product met its published specifications at the time of shipment from
the factory. VTI further certifies that its calibration measurements are traceable to the United States National
Institute of Standards and Technology (formerly National Bureau of Standards), to the extent allowed by that
organization’s calibration facility, and to the calibration facilities of other International Standards Organization
members.
WARRANTY
The product referred to herein is warranted against defects in material and workmanship for a period of one year
from the receipt date of the product at customer’s facility. The sole and exclusive remedy for breach of any warranty
concerning these goods shall be repair or replacement of defective parts, or a refund of the purchase price, to be
determined at the option of VTI.
For warranty service or repair, this product must be returned to a VXI Technology authorized service center. The
product shall be shipped prepaid to VTI and VTI shall prepay all returns of the product to the buyer. However, the
buyer shall pay all shipping charges, duties, and taxes for products returned to VTI from another country.
VTI warrants that its software and firmware designated by VTI for use with a product will execute its programming
when properly installed on that product. VTI does not however warrant that the operation of the product, or
software, or firmware will be uninterrupted or error free.
LIMITATION OF WARRANTY
The warranty shall not apply to defects resulting from improper or inadequate maintenance by the buyer, buyersupplied products or interfacing, unauthorized modification or misuse, operation outside the environmental
specifications for the product, or improper site preparation or maintenance.
VXI Technology, Inc. shall not be liable for injury to property other than the goods themselves. Other than the
limited warranty stated above, VXI Technology, Inc. makes no other warranties, express or implied, with respect to
the quality of product beyond the description of the goods on the face of the contract. VTI specifically disclaims the
implied warranties of merchantability and fitness for a particular purpose.
RESTRICTED RIGHTS LEGEND
Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subdivision (b)(3)(ii) of the
Rights in Technical Data and Computer Software clause in DFARS 252.227-7013.
VXI Technology, Inc.
2031 Main Street
Irvine, CA 92614-6509 U.S.A.
SVM2608 Preface 5
VXI Technology, Inc.
D ECLARATION OF C ONFORMITY
Declaration of Conformity According to ISO/IEC Guide 22 and EN 45014
ANUFACTURER’S NAME VXI Technology, Inc.
M
ANUFACTURER’S ADDRESS 2031 Main Street
M
Irvine, California 92614-6509-6509
RODUCT NAME 4-Channel, 100 kSamples/s Analog-to-Digital Converter
P
ODEL NUMBER(S) SVM2608
M
RODUCT OPTIONS All
P
RODUCT CONFIGURATIONS All
P
VXI Technology, Inc. declares that the aforementioned product conforms to the requirements of
the Low Voltage Directive 73/23/EEC and the EMC Directive 89/366/EEC (inclusive 93/68/EEC)
and carries the “CE” mark accordingly. The product has been designed and manufactured
according to the following specifications:
AFETY EN61010 (2001)
S
EMC EN61326 (1997 w/A1:98) Class A
CISPR 22 (1997) Class A
VCCI (April 2000) Class A
ICES-003 Class A (ANSI C63.4 1992)
AS/NZS 3548 (w/A1 & A2:97) Class A
FCC Part 15 Subpart B Class A
EN 61010-1:2001
The product was installed into a C-size VXI mainframe chassis and tested in a typical configuration.
I hereby declare that the aforementioned product has been designed to be in compliance with the relevant sections
of the specifications listed above as well as complying with all essential requirements of the Low Voltage Directive.
February 2007
Steve Mauga, QA Manager
6 SVM2608 Preface
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Review the following safety precautions to avoid bodily injury and/or damage to the product.
These precautions must be observed during all phases of operation or service of this product.
Failure to comply with these precautions or with specific warnings elsewhere in this manual,
violates safety standards of design, manufacture and intended use of the product.
Service should only be performed by qualified personnel.
TERMS AND SYMBOLS
These terms may appear in this manual:
WARNING
CAUTION
These symbols may appear on the product:
GENERAL SAFETY INSTRUCTIONS
Indicates that a procedure or condition may cause bodily injury or death.
Indicates that a procedure or condition could possibly cause damage to
equipment or loss of data.
WARNINGS
ATTENTION - Important safety instructions
Frame or chassis ground
Indicates that the product was manufactured after August 13, 2005. This mark is
placed in accordance with EN 50419, Marking of electrical and electronic
equipment in accordance with Article 11(2) of Directive 2002/96/EC (WEEE).
End-of-life product can be returned to VTI by obtaining an RMA number. Fees
for take-back and recycling will apply if not prohibited by national law.
Follow these precautions to avoid injury or damage to the product:
Use Proper Power Cord
To avoid hazard, only use the power cord specified for this
product.
Use Proper Power Source
To avoid electrical overload, electric shock or fire hazard, do
not use a power source that applies other than the specified
voltage.
Use Proper Fuse
To avoid fire hazard, only use the type and rating fuse
specified for this product.
SVM2608 Preface 7
WARNINGS (CONT.)
Avoid Electric Shock
Ground the Product
Operating Conditions
Improper Use
VXI Technology, Inc.
To avoid electric shock or fire hazard, do not operate this product
with the covers removed. Do not connect or disconnect any cable,
probes, test leads, etc. while they are connected to a voltage source.
Remove all power and unplug unit before performing any service.
Service should only be performed by qualified personnel.
This product is grounded through the grounding conductor of the
power cord. To avoid electric shock, the grounding conductor must
be connected to earth ground.
To avoid injury, electric shock or fire hazard:
- Do not operate in wet or damp conditions.
- Do not operate in an explosive atmosphere.
- Operate or store only in specified temperature range.
- Provide proper clearance for product ventilation to prevent
overheating.
- DO NOT operate if any damage to this product is suspected.
Product should be inspected or serviced only by qualified
personnel.
The operator of this instrument is advised that if the equipment is
used in a manner not specified in this manual, the protection
provided by the equipment may be impaired. Conformity is checked
by inspection.
8 SVM2608 Table of Contents
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Visit
SUPPORT RESOURCES
Support resources for this product are available on the Internet and at VXI Technology customer
support centers.
VXI Technology
World Headquarters
VXI Technology, Inc.
2031 Main Street
Irvine, CA 92614-6509
Phone: (949) 955-1894
Fax: (949) 955-3041
VXI Technology
Cleveland Instrument Division
5425 Warner Road
Suite 13
Valley View, OH 44125
Phone: (216) 447-8950
Fax: (216) 447-8951
VXI Technology
Lake Stevens Instrument Division
VXI Technology, Inc.
1924 - 203 Bickford
Snohomish, WA 98290
Phone: (425) 212-2285
Fax: (425) 212-2289
Technical Support
Phone: (949) 955-1894
Fax: (949) 955-3041
E-mail:
support@vxitech.com
http://www.vxitech.com for worldwide support sites and service plan information.
SVM2608 Preface 9
VXI Technology, Inc.
10 SVM2608 Preface
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SECTION 1
INTRODUCTION
INTRODUCTION
The SVM Series leverages off VXI Technology’s line of high-density modular VXIbus
instruments, but are optimized for the VMEbus. All SVM instruments are designed to provide all
the features of test instrumentation in other platforms such as GPIB or VXI. These features are
achieved in hardware rather than in a driver. This approach to the interface design guarantees the
user that all communications to the module occur in microseconds, as opposed to several
milliseconds, considerably improving system throughput. The board is equipped with a
microprocessor which significantly increases the module’s functionality and task performing
capabilities.
The SVM2608 is a ruggedized circuit card designed for insertion into a convection-cooled VME
chassis. It is a double height VME size module (6U) of single slot width and conforms to all
physical requirements as specified by VME specifications. The VME interface is compatible with
the VME32/64x configuration with two 160-pin (32 x 5) backplane connectors (P0 – P1). The
SVM2608 consists of four low-speed (100 kSamples/s) channels and, with the addition of the -01
Option, can include two, high-speed (20 MHz) channels.
OVERVIEW
The SVM2608 is a precision, four channel digitizer capable of capturing data on all four channels
simultaneously either in FIFO (or “real-time”) mode or Linear (or “burst”) mode. A processor
enables the user to perform a variety of calculations with the data acquired. Each channel is also
capable of measuring voltage and resistance. All four channels can measure voltage at the same
time, but resistance can only be measured one channel at a time. Resistance can be measured in
two different modes: 2-wire or 4-wire. Both modes use a local current source to inject a current
into the resistor under test and then measure voltage across the resistor.
All four channels are independent of one another. The front end of each channel has both a
variable gain amplifier and an attenuator, thus allowing for full ADC scale measurements of
signals from 1 V to 100 V. Before being digitized, the signal can be passed through a Low Pass
Filter (LFP) with a cut-off frequency of 20 kHz. The ADC is a 16-bit converter capable of taking
as many as 100 kSamples/s on a scale of -10 V to +10 V. To compensate for offset and gain
variation in the ADCs, each channel has two 12-bit DACs that are used to calibrate the offset and
the gain on each channel ADC. These calibrations are performed at the factory using precision
voltage reference sources.
SVM2608 Introduction 11
CHn +I
CHn+
CHn–
CHnI–
EXT TRIG
VXI Technology, Inc.
DATA
ADDRESS
VME INT ERFACE
CON TROL S
÷ 1
÷ 10
DAC
1x, 2x, 5x, 10x
attn
GLUE LO GIC
+
–
gain1
gain0
+
–
TRIG
LPF
FILTER
DAC
EXT TRIG
FORC E
POL
ADC
16
+
–
MEMORY
CHANNEL 0
TRIG
CHANNEL 1 TRIG
CHANNEL 2 TRIG
CHANNEL 3 TRIG
μP
DATA &
CONTROLS
DATA & CONTROL
FIGURE 1-1: SVM2608 BLOCK DIAGRAM
The acquisition process is controlled by two FPGAs that allow for greater flexibility along with
higher speed and precision during the digitizing process. As the data is digitized, it is placed in
memory. It is then available to the user through the VME interface. Each channel has its own
channel memory that can store up to one million samples of data. This data is also made available
to the microprocessor for data processing. The samples are stored as words (16 bits). The first
sample of a channel is located at the channel’s base address at Offset 0 (0x000000 for Channel 0,
0x200000 for Channel 1, 0x400000 for Channel 2 and 0x600000 for Channel 3). The next sample
is located at Offset 2 (0x000002 for Channel 0, etc.) and the third sample is located at Offset 4,
etc.
In order to provide better resolution for the measurement, the input signal is amplified
accordingly to generate a ±10 V
weight of a bit of digitized data will be different:
The following equation is used to determine the bit weight at a specified scale:
Bit Weight = Full Scale / 32,768
For example, the Bit Weight of the 10 V range is:
10.0 volts / 32768 = 0.0003051757813 V/count
≈ 305.176 µV/count
signal at the input of the ADC. Thus, on different scales, the
P-P
SCALE (V) Bit Weight (μV/count)
1 30.518
2 61.035
5 152.588
10 305.176
20 610.352
50 1525.879
VME BAC KPLANE
12 SVM2608 Introduction
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The counts stored in memory are 16 bits SIGNED integers. The most significant bit represents
the SIGN. Thus, the hex number 0x4000 and the hex number of 0xC000 represent the same
signal amplitude but in opposite directions, where 0x4000 represents a positive signal while
0xC000 is a negative signal with the same amplitude.
To translate a raw count value into a voltage, multiply the raw count value by the bit weight. The
following example shows this conversion for a SVM2608 using the 10.0 V range:
A reading of 0x4000 = 16,384 counts
Voltage = Counts * Bit Weight
Voltage = 16384 counts* 305.176 µV/count
≈ 5.0 volts.
A reading of 0xC000 = -16,384 counts
Voltage = -16384 counts * 305.176 µV/count
≈ -5.0 volts.
Similarly, for the 5 volt range:
A reading of 0x4000 = 16,384 counts
Voltage = 16,384 counts * 152.588 µV/count
≈ 2.5 volts.
Data acquisition can be made in two modes: Linear or FIFO. In FIFO mode, data can only be
read from a fixed address (FIFO register), while in Linear mode, data can be read from any
address in the memory space of a channel. Linear mode also offers a two more options for
acquisition: Pre-Trigger and Delayed Trigger.
In FIFO mode, data can be retrieved while the acquisition is still in progress. However, if the
memory is not read and the acquisition continues running, new incoming data will overwrite
older data and the older data will be lost. It is also NOT possible to run a measurement command
in FIFO mode.
Acquiring Data
To acquire data, a channel must first be Armed. When a channel is armed, it starts its local
Sample Clock and waits for a Trigger Event to begin sampling. The channel must remain Armed
for the entire duration of the acquisition process. Clearing the ARM bit will reset the internal
state-machines and stop acquisition. Data capturing starts when a Trigger Event occurs. A trigger
event can be caused by an external trigger source, the signal under test or forced by setting a bit
in a register.
Triggering
An external signal, other than one of the sampled signals, can be used to trigger any or all of the
channels. This external signal is compared to a threshold level set by a local DAC and a highspeed comparator is used to generate an External Trigger signal.
The signal under test can also be used to trigger an acquisition. The signal is compared to a
threshold level set by a local DAC and a high-speed comparator is used to generate a Channel
Trigger signal. Each channel has its own DAC and its own comparator, thus, each channel can
generate a Trigger signal independent of the other channels. Acquisition on any channel can be
triggered by any other Channel Trigger signal (Channel 0 can be triggered by Channel 0 Trigger,
Channel 1 Trigger, Channel 2 Trigger, or Channel 3 Trigger) even if the other channels are not
armed and are not acquiring any data. Only one channel can be the trigger source at any time and
the trigger sources cannot be AND’ed or OR’ed together.
SVM2608 Introduction 13
VXI Technology, Inc.
In absence of a Trigger signal, the acquisition can be forced by setting a control bit, the FORCE
bit. Forcing an acquisition on a channel only starts acquisition on that channel. Each channel has
its own corresponding FORCE bit.
Linear Mode
In Linear mode, the total number of samples collected (also referred to as Sample Points) is
determined by the value programmed into the Sample Points register. The first sample (also
referred to as Sample Zero) is stored in memory when a Trigger Event occurs. Sample Zero is
from the value read from the channel’s base address at offset zero (0x000000 for Channel 0,
0x200000 for Channel 1, 0x400000 for Channel 2 and 0x600000 for Channel 3).
Pre-Trigger
In Linear mode, it is also possible to store samples that occur before a Trigger Event. When a
channel is armed and the Pre-Trigger register is programmed with a value other than zero, that
channel will begin sampling immediately, without waiting for an External Trigger. After it stores
the number of samples specified in the Pre-Trigger register (also referred to as Pre-Trigger
Points), it begins monitoring the Trigger Event. Until the Trigger Event occurs, the channel
continues sampling and storing. When the Trigger Event occurs, Sample Zero is stored. After the
Trigger Event, the number of data points collected is determined by the following equation:
AFTER TRIGGER POINTS = SAMPLE POINTS – PRETRIGGER POINTS
When the user reads from offset zero of a channel, the data returned is Sample Zero followed by
Sample Zero + 1, etc. The Pre-Trigger Points can be read from the top of that channel’s memory.
For example, if 0x100 Pre-Trigger Points were sampled on Channel 0 after the acquisition is
completed, the samples can be retrieved from locations 0x1FFE00, 0x1FFE02 …0x1FFFFE with
the data at 0x1FFFFE being the last Pre-Trigger Sample before the trigger event.
Delayed Trigger
In Linear mode, it is also possible to delay storing Sample Zero by a number of sample clocks,
where a sample clock is defined by the Sample Clock Rate register. The number of sample clocks
an acquisition is delayed (also referred to as Delayed Points) is programmed in the Delayed
Trigger register. Samples are taken and stored immediately when the Trigger Event occurs, but
Sample Zero will be stored only after the specified number of Delayed Points passes. Data stored
during the Delayed period can be viewed by the user at the top of the memory space of the
respective channel (same as in Pre-Trigger mode as above), assuming that the following
condition is observed:
SAMPLE POINTS < 1 MSamples
As opposed to the Pre-Trigger acquisition, the number of samples taken after the Trigger Event is
not affected by the number of samples taken before it:
AFTER TRIGGER POINTS = SAMPLE POINTS
If the following condition is met:
DELAYED POINTS < 1 M – SAMPLE POINTS
Then all the samples collected before the Trigger Event are available to the user.
14 SVM2608 Introduction
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FIFO Mode
In FIFO mode, the user can retrieve data from the board as acquisition progresses. The memory
behaves as a FIFO: data is written into a circular buffer with new data overwriting older data
when the buffer is full. A Threshold Flag is available to monitor the status of the buffer and
prevent overwriting the data or under-reading it.
The Sample Points register that is used in Linear mode to determine the amount of data to be
captured is used in FIFO mode to determine the size associated with the FIFO Threshold Flag.
When the number of samples stored in memory equals the number of points set in the Sample
Points register, the FIFO Threshold flag is asserted. In this manner, the user can wait until a
certain number of samples are captured before they download data from the board. If the user
fails to retrieve the data from the card in time and new data overwrites older data, then the FIFO
Overrun flag is asserted. Conversely, if the user attempts to read more data than has been stored,
the FIFO Underrun flag is asserted. The FIFO Threshold flag is cleared when data is read from
the board and the total amount of “new (unread)” data in the buffer is less than the THRESHOLD
value. The FIFO Overrun and Underrun flags are cleared only when a new acquisition is
initiated.
Calibrations
Due to the nature of the semiconductors and passive components, not all parts have exactly the
same characteristics. Slight differences exist from component to component. While these
inconsistencies are unavoidable, they do not affect the basic functionality of the electronic
instrumentation. The precision of the instrument, however, can be altered by these variances.
One way to eliminate these slight variations is to use expensive, precision parts or to perform a
rigorous parts selection procedure to ensure consistency. These measures, however, would
dramatically increase the cost of the board. Another way to compensate for offset and gain
variations is to take a number of measurements using precision calibrated instruments of known
voltage and resistance. Their known values are then compared against the values attained for
each channel and the difference is used to adjust future measurements. These adjustments are
called calibrations. They are performed at the factory using approved calibration sources.
Test Bus
The SVM2608 is capable of performing a self-test to check for functionality and accuracy. Using
a local voltage reference source and local resistance references, basic function tests can be
performed. Four different voltage reference sources are available on the board: ±9.45 V and
±0.945 V. Two Resistance References are available: 128 Ω and 81.92 kΩ. Two different signal
generators can also be used for different tests: a RAMP generator and a PULSE generator. Any
of these locally generated test sources can be placed on the internal Test Bus (TB). The Test Bus
can then be connected to the input of any or all of the channels. Only one of the test signals can
be connected to the Test Bus at one time. The test sources can be connected to the Test Bus using
microprocessor commands. The Test Bus is also available to the user for monitoring on pins 24
and 13 of the Front Panel Connector. (See
Front Panel Interface Wiring for more detail.)
The self-test is performed by sending a command to the microprocessor, instructing it to run the
self-test (see
3Microprocessor Commands). When the microprocessor runs the self-test, a Test
Result is returned (see the description of the Self Test Command for a more detailed description).
Commands
The SVM2608 is equipped with a processor. While the processor is not directly involved in the
acquisition process, its presence on the board significantly enhances the capabilities of the
SVM2608 digitizer.
The user can choose to download the data on to a CPU and perform custom data processing, or
they can instruct the on-board microprocessor to perform one or several predefined calculations
SVM2608 Introduction 15
VXI Technology, Inc.
sets. (See 3Microprocessor Commands for more details on available commands.) The command is
sent to the microprocessor via the Command register. Since there are four independent channels
on the board, each of them can take a different command and each of them has its own command
register. The result of the microprocessor calculation is returned in the Result register for the
corresponding channel.
The data stored in the channel memory is raw data. When the microprocessor performs a
resistance calculation, it uses calibrated data, meaning that the microprocessor takes the
calibrations for the Local Current Sources (see above) values into consideration. The raw data the
user downloads from the board represents calibrated voltage measurements. The result calculated
by the microprocessor and placed in the Result register when a Resistance Measurement
command is issued is based on calibrated Current measurements. While the user can perform
calibrated voltage measurements by simply reading the raw data, the calculations for resistance
cannot be accurately performed by the user as they do not have the calibrated current values (the
exact values injected in the resistance under test by the board’s current source). Although it is
possible for the user to read the calibration values (see the
Calibration Commands section) and
use the raw data to perform all the calibrated measurements on their own, the manufacturer
encourages the use of the microprocessor’s capabilities to perform all calibrated resistance
calculations.
Option -01
With the addition of the SVM2608-01 option, two additional channels are available with a
sample rate of 20 MHz and 12-bits of resolution. This option may be purchased at the same time
as the SVM2608 or is factory upgradeable.
The high-speed channels available on Option -01 function independently. The front end of each
channel has both a variable gain amplifier and an attenuator, similar to the low-speed channels. A
5 MHz low-pass filter (LPF) is available on these channels, as opposed to the 20 kHz LPF found
on the low-speed channels. The ADC converter is a 12 bits converter capable of taking as many
as 20 MSamples/s on a scale of -2 V to +2 V. To compensate for offset and gain variation in the
ADCs, each channel has two 12 bits DACs that are used to calibrate the offset and the gain on
each ADC channel. These calibrations are performed at the factory using precision voltage
reference sources. A block diagram for Option -01 is provided on the following page.
16 SVM2608 Introduction
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HS_CHnI+
50 Ohm
HS_CHn–
50 Ohm
HS_EXT_TRIG
EXT_TRIG_LVL
GLUE LOGIC
12 BITS
CHANNEL_1 TRIG
TRIG
CHANNEL_5 TRIG
EXT_TRG
TO
SINGLE
HIGH SPEED
CHANNEL
ADC
16 BITS, 120 MHz
÷ 1
÷ 10
+
DIFF TO
SINGLE
÷ 1
÷ 10
TRIG_LVL
–
DAC
LPF
OFFSET_LVL
+
–
+
–
DAC
DAC
REF_LVL
CHNL TRIG
1x, 2x, 4x
+
–
OFFSET
ADJ
DAC
+
SINGLE
DIFF
–
REFERENCE
CHNL TRIG
SDRAM
2 MB
ADJ
VM2608
MAIN BOA RD
LOW_SPEED_CHNLS
16 BITS, 10 MHz
REF_LVL
TRIG_LVL
OFFSET_LVL
HS_TRIG_LVL
DATA &
CONTROLS
LS_TRIG
HS_TRIG
FIGURE 1-2: SVM2608 BLOCK DIAGRAM
SVM2608 Introduction 17
CH 4 +
VXI Technology, Inc.
PHYSICAL DESCRIPTION
The SVM2608 has a protective coating applied to it to ensure that the effects of environmental
hazards are minimized. This coating endows the modules with resistance to salt sprays, moisture,
dust, sand, and explosive environments, as the polymer coating provides a hermetic seal. The
module is designed to withstand the stress and rigors of shock and vibration, allowing the module
P/FA/E
to be deployed in a variety of applications without concern for damage due to the surrounding
physical environment. The following table details the environmental specifications of this
module.
CH 4 -
HS TRIG
CH 5 +
CH 5 -
J100
TABLE 1-1: SVM2608 ENVIRONMENTAL SPECIFICATIONS
SVM ENVIRONMENTAL SPECIFICATIONS
CLASSIFICATION
TEMPERATURE
OPERATIONAL
NON-OPERATIONAL
HUMIDITY
ALTITUDE
OPERATIONAL
SUSTAINED STORAGE
RANDOM VIBRATION
O
PERATIONAL
ON-OPERATIONAL
N
FUNCTIONAL SHOCK
SALT ATMOSPHERE
SAND AND DUST
The SVM2608 has two indicator LEDs located on its front panel. The A/E (Access/Error) LED
flashes green when read/write commands are being sent to the module. Should the SVM2608
receive an error, the LED glows red. This LED can be overridden by the user by setting the Sysfail
bit in the
Reset, Sys Fail Control, Interrupt Levels Register. The P/F (Power/Fail) LED glows
green indicates the status of a processor driven self-test. If the self-test is successful, the P/F LED
glows green, if the test fails, however, the LED will glow red. Both the A/E and P/F LEDs can be
programmed to glow red when a fail condition occurs.
MIL-T-28800E Type III, Class 5, Style E or F
Meets functional shock requirements of MIL-T-28800E, Type III, Class 5
-20°C to 65°C
-40°C to 71°C
5% to 95% (non-condensing)
Sea level to 15,000 ft (4,570 m)
Sea level to 40,000 ft (12,190 m)
Three axis, 30 minutes total, 10 minutes per axis
0.27 g
2.28 g
total from 5.0 Hz to 55.0 Hz
rms
total from 5.0 Hz to 55.0 Hz
rms
Half sine, 30 g, 11 ms duration
> 48 hrs operation
> 6 hrs operation in a dust environment of 0.3 g/ft3 blowing at 1750 ft/min
FIGURE 1-3: SVM2608 FRONT PANEL
18 SVM2608 Introduction
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