DAQ SCXI-1102 User manual

SCXI
™
-1102/B/C
User Manual
32-Channel Thermocouple Amplifier Modules
SCXI-1102/B/C User Manual
August 1997 Edition
Part Number 320975B-01
© Copyright 1995, 1997 National Instruments Corporation. All rights reserved.

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Important Information
Warranty
The SCXI-1102, SCXI-1102B, and SCXI-1102C modules are warranted against defects in materials and workmanship
for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National
Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period. This
warranty includes parts and labor.
The media on which you receive National Instruments software are warranted not to fail to execute programming
instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced
by receipts or other documentation. National Instruments will, at its option, repair or replace software media that do
not execute programming instructions if National Instruments receives notice of such defects during the warranty
period. National Instruments does not warrant that the operation of the software shall be uninterrupted or error free.
A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the outside
of the package before any equipment will be accepted for warranty work. National Instruments will pay the shipping
costs of returning to the owner parts which are covered by warranty.
National Instruments believes that the information in this manual is accurate. The document has been carefully
reviewed for technical accuracy. In the event that technical ortypographical errors exist, National Instruments reserves
the right to make changes to subsequent editions of this document without prior notice to holders of this edition. The
reader should consult National Instruments if errors are suspected. In no event shall National Instruments be liable for
any damages arising out of or related to this document or the information contained in it.
EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED, AND
SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR APARTICULAR PURPOSE.
CUSTOMER’SRIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL
INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER. NATIONAL INSTRUMENTS
WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA, PROFITS, USE OF PRODUCTS, OR INCIDENTAL OR
CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY THEREOF. This limitation of the liability of National
Instruments will apply regardless of the form of action, whether in contract or tort, including negligence. Any action
against National Instruments must be brought within one year after the cause of action accrues. National Instruments
shall not be liable for any delay in performance due to causes beyond its reasonable control. The warranty provided
herein does not cover damages, defects, malfunctions, or service failures caused by owner’s failure to follow the
National Instruments installation, operation, or maintenance instructions; owner’s modification of the product;
owner’s abuse, misuse, or negligent acts; and power failure or surges, fire, flood, accident, actions of third parties, or
other events outside reasonable control.
Copyright
Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical,
including photocopying, recording, storing in an information retrieval system, or translating, in whole or in part,
without the prior written consent of National Instruments Corporation.
Trademarks
LabVIEW®, NI-DAQ®, RTSI®, ComponentWorks™, CVI™, DAQCard™, DAQPad™, Measure™, SCXI™, and
VirtualBench™are trademarks of National Instruments Corporation.
Product and company names listed are trademarks or trade names of their respective companies.
WARNING REGARDING MEDICAL AND CLINICAL USE OF NATIONAL INSTRUMENTS PRODUCTS
National Instruments products are not designed with components and testing intended to ensure a level of reliability
suitable for use in treatment and diagnosis of humans. Applications of National Instruments products involving
medical or clinical treatment can create a potential for accidental injury caused by product failure, or by errors on the
part of the user or application designer. Any use or application of National Instruments products for or involving
medical or clinical treatment must be performed by properly trained and qualified medical personnel, and all traditional
medical safeguards, equipment, and procedures that are appropriate in the particular situation to prevent serious injury
or death should always continue to be used when National Instruments products are being used. National Instruments
products are NOT intended to be a substitute for any form of established process, procedure, or equipment used to
monitor or safeguard human health and safety in medical or clinical treatment.

© National Instruments Corporation v SCXI-1102/B/C User Manual
Table
of
Contents
About This Manual
Organization of This Manual...........................................................................................ix
Conventions Used in This Manual...................................................................................x
National Instruments Documentation..............................................................................xi
Customer Communication...............................................................................................xii
Chapter 1
Introduction
About the SCXI-1102/B/C Modules................................................................................1-1
What You Need to Get Started ........................................................................................1-2
Software Programming Choices......................................................................................1-3
National Instruments Application Software......................................................1-3
NI-DAQ Driver Software..................................................................................1-4
Register-Level Programming ............................................................................1-5
Optional Equipment.........................................................................................................1-5
Custom Cables.................................................................................................................1-6
Unpacking........................................................................................................................1-6
Chapter 2
Configuration and Installation
Module Configuration......................................................................................................2-1
Digital Configuration.........................................................................................2-3
Analog Configuration........................................................................................2-4
Current-Loop Receivers......................................................................2-4
Hardware Installation.......................................................................................................2-6
Chapter 3
Signal Connections
Front Connector...............................................................................................................3-1
Front Connector Signal Descriptions ................................................................3-3
Analog Input Signal Connections.......................................................3-3
Ground-Referencing Your Signals.......................................3-4
Cold-Junction Sensor Connection.....................................................................3-6

Table of Contents
SCXI-1102/B/C User Manual vi
© National Instruments Corporation
Rear Signal Connector..................................................................................................... 3-7
Rear Signal Connector Descriptions................................................................. 3-8
Analog Output Signal Connections.................................................... 3-9
Digital I/O Signal Connections...........................................................3-9
Digital Timing Signal Connection......................................................3-10
Digital Signal Specifications ..............................................................3-10
Chapter 4
Theory of Operation
Functional Overview.......................................................................................................4-1
Rear Signal Connector, SCXIbus Connector, and SCXIbus Interface............. 4-2
Digital Control Circuitry...................................................................................4-2
Analog Circuitry ...............................................................................................4-3
Analog Input Channels.......................................................................4-3
Analog Bus Switch.............................................................................4-4
Chapter 5
Calibration
Overview .........................................................................................................................5-1
Calibration Procedure......................................................................................................5-1
Calibration Equipment Requirements...............................................................5-1
Gain and Offset Calibration..............................................................................5-2
Appendix A
Specifications
Appendix B
Calibration Sample Program
Appendix C
Customer Communication
Glossary
Index

Table of Contents
© National Instruments Corporation vii SCXI-1102/B/C User Manual
Figures
Figure 1-1. The Relationship between the Programming Environment,
NI-DAQ, and Your Hardware.................................................................1-4
Figure 2-1. SCXI-1102/B/C Module Parts Locator Diagram (1102 shown).............2-2
Figure 2-2. Removing the SCXI Module Cover........................................................2-4
Figure 2-3. Bent and Trimmed Resistor.....................................................................2-5
Figure 3-1. SCXI-1102/B/C Module Front Connector Pin Assignments ..................3-2
Figure 3-2. Ground-Referenced Signal Connection...................................................3-5
Figure 3-3. Floating Signal Connection Referenced to Chassis Ground...................3-6
Figure 3-4. SCXI-1102/B/C Module Rear Signal Connector Pin Assignments........3-7
Figure 4-1. SCXI-1102/B/C Module Block Diagram................................................4-1
Tables
Table 2-1. Jumper Settings for Digital Signal Connection.......................................2-3
Table 3-1. SCXIbus to SCXI-1102/B/C Module Rear Signal Connector
to DAQ Device Pin Equivalencies..........................................................3-10

© National Instruments Corporation ix SCXI-1102/B/C User Manual
About
This
Manual
This manual describes the electrical and mechanical aspects of the
SCXI-1102 family of modules and contains information concerning
their installation and operation.
The SCXI-1102 family consists of the following modules:
• SCXI-1102
• SCXI-1102B
• SCXI-1102C
Unless otherwise noted, SCXI-1102/B/C will hereafter refer to all three
modules in the SCXI-1102 family.
The SCXI-1102/B/C modules are members of the National Instruments
Signal Conditioning eXtensions for Instrumentation (SCXI) Series for
the National Instruments data acquisition (DAQ) plug-in devices. These
modules are designed for signal conditioning thermocouples, volt and
millivolt sources, and 4–20 mA sources or 0–20 mA process-current
sources. The SCXI-1102/B/C modules have 32 differential analog input
channels and one cold-junction sensor channel.
Organization of This Manual
The SCXI-1102/B/C User Manual is organized as follows:
• Chapter 1, Introduction, describes the SCXI-1102/B/C modules;
lists what you need to get started with your SCXI-1102/B/C
module, the optional software, optional equipment, and custom
cables; and explains how to unpack the SCXI-1102/B/C modules.
• Chapter 2, Configuration and Installation, describes how to
configure the SCXI-1102/B/C jumper, how to install current-loop
receivers, and how to install the SCXI-1102/B/C module into the
SCXI chassis.
• Chapter 3, Signal Connections, describes the input and output
signal connections to the SCXI-1102/B/C module via the module
front connector and rear signal connector. This chapter also

About This Manual
SCXI-1102/B/C User Manual x
© National Instruments Corporation
includes specifications and connection instructions for the signals
on the SCXI-1102/B/C connectors.
• Chapter 4, Theory of Operation, contains a functional overview of
the SCXI-1102/B/C module and explains the operation of each
functional unit making up the SCXI-1102/B/C module.
• Chapter 5, Calibration, discusses the calibration procedures for the
SCXI-1102/B/C modules.
• Appendix A, Specifications, lists the specifications for the
SCXI-1102/B/C modules.
• Appendix B, Calibration Sample Program, contains a sample
program to help you calibrate your submodule.
• Appendix C, Customer Communication, contains forms you can
use to request help from National Instruments or to comment on our
products.
•TheGlossary contains an alphabetical list and description of terms
used in this manual, including abbreviations, acronyms, metric
prefixes, mnemonics, symbols, and terms.
•TheIndex contains an alphabetical list of key terms and topics in
this manual, including the page where you can find each one.
Conventions Used in This Manual
The following conventions are used in this manual.
♦The ♦symbol indicates that the text following it applies only to specific
SCXI-1102 modules.
< > Angle brackets containing numbers separated by an ellipsis represent a
range of values associated with a port, bit, or signal name (for example,
ACH<0..7> stands for the signals ACH0 through ACH7).
This icon to the left of bold italicized text denotes a note, which alerts
you to important information.
This icon to the left of bold italicized text denotes a caution, which
advises you of precautions to take to avoid injury, data loss, or a
system crash.
bold italic Bold italic text denotes a note, caution, or warning.
italic Italic text denotes emphasis, a cross reference, or an introduction to a
key concept.
Lab board Refers to the boards that have Lab in their names, such as the Lab-LC
and the Lab-PC+.
!

About This Manual
© National Instruments Corporation xi SCXI-1102/B/C User Manual
MIO board Refers to the multichannel I/O DAQ boards that have MIO in their
names, such as the AT-MIO-16 and the NEC-MIO-16E-4.
monospace Denotes text or characters that are to be literally input from the
keyboard, sections of code, programming examples, and syntax
examples. This font is also used for the proper names of disk drives,
paths, directories, programs, subprograms, subroutines, device names,
functions, variables, filenames, and extensions, and for statements and
comments taken from program code.
PC Refers to the IBM PC/XT, the IBM PC AT, and compatible computers.
SCXIbus Refers to the backplane in the chassis. A signal on the backplane is
referred to as the SCXIbus <signal name> line (or signal). The SCXIbus
descriptor may be omitted when the meaning is clear. Descriptions of
all SCXIbus signals are in Chapter 3, Signal Connections.
SCXI-1102/B/C Refers to all modules in the SCXI-1102 family unless otherwise noted.
modules
Slot 0 Refers to the power supply and control circuitry in the SCXI chassis.
Abbreviations, acronyms, metric prefixes, mnemonics, symbols, and
terms are listed in the Glossary.
National Instruments Documentation
The SCXI™-1102/B/C User Manual is one piece of the documentation
set for your data acquisition system. You could have any of several
types of manuals, depending on the hardware and software in your
system. Use the manuals you have as follows:
•Getting Started with SCXI—This is the first manual you should read.
It gives an overview of the SCXI system and contains the most
commonly needed information for the modules, chassis, and
software.
• Your SCXI hardware user manuals—Read these manuals next for
detailed information about signal connections and module
configuration. They also explain in greater detail how the module
works and contain application hints.
• Your DAQ hardware user manuals—These manuals have detailed
information about the DAQ hardware that plugs into or is
connected to your computer. Use these manuals for hardware
installation and configuration instructions, specification
information about your DAQ hardware, and application hints.

About This Manual
SCXI-1102/B/C User Manual xii
© National Instruments Corporation
• Software documentation—Examples of software documentation
you may have are the LabVIEW and LabWindows®/CVI manual
sets and the NI-DAQ documentation. After you set up your
hardware system, use either the application software
documentation or the NI-DAQ documentation to help you write
your application. If you have a large and complicated system, it is
worthwhile to look through the software documentation before you
configure your hardware.
• Accessory installation guides or manuals—If you are using
accessory products, read the terminal block and cable assembly
installation guides. They explain how to physically connect the
relevant pieces of the system. Consult these guides when you are
making your connections.
•SCXI Chassis Manual—Read this manual for maintenance
information on the chassis and installation instructions.
Customer Communication
National Instruments wants to receive your comments on our products
and manuals. We are interested in the applications you develop with our
products, and we want tohelp if you have problems with them. To make
it easy for you to contact us, this manual contains comment and
configuration forms for you to complete. These forms are in
Appendix C, Customer Communication, at the end of this manual.

© National Instruments Corporation 1-1 SCXI-1102/B/C User Manual
Chapter
1
Introduction
This chapter describes the SCXI-1102/B/C modules; lists what you
need to get started with your SCXI-1102/B/C module, the optional
software, optional equipment, and custom cables; and explains how to
unpack the SCXI-1102/B/C modules.
About the SCXI-1102/B/C Modules
♦SCXI-1102
This module is for signal conditioning of thermocouples,
low-bandwidth volt and millivolt sources, 4 to 20 mA current sources,
and 0 to 20 mA process-current sources. The SCXI-1102 has
32 differential analog input channels and one cold-junction sensor
channel. On each channel, the SCXI-1102 has a three-pole lowpass
filter with a 2 Hz cutoff frequency to reject 60 Hz noise. Each channel
also has an amplifier with a selectable gain of 1 or 100. You can
multiplex the SCXI-1102 inputs to a single output, which drives a single
DAQ device channel.
♦SCXI-1102B
This module is for the signal conditioning of thermocouples,
medium-bandwidth volt and millivolt sources, 4 to 20 mA current
sources, and 0 to 20 mA process-current sources. The SCXI-1102B has
32 different analog input channels and one cold-junction sensor
channel. On each channel, the SCXI-1102B has a three-pole lowpass
filter with a 200 Hz cutoff frequency. Each channel also has an
amplifier with a selectable gain of 1 or 100. You can multiplex the
SCXI-1102B inputs to a single output, which drives a single DAQ
device channel.
♦SCXI-1102C
This module is for the signal conditioning of thermocouples,
high-bandwidth volt and millivolt sources, 4 to 20 mA current sources,
and 0 to 20 mA process-current sources. The SCXI-1102C has 32
different analog input channels and one cold-junction sensor channel.
On each channel, the SCXI-1102C has a three-pole lowpass filter with
a 10 kHz cutoff frequency. Each channel also has an amplifier with a

Chapter 1 Introduction
SCXI-1102/B/C User Manual 1-2
© National Instruments Corporation
selectable gain of 1 or 100. You can multiplex the SCXI-1102C inputs
to a single output, which drives a single DAQ device channel.
The SCXI-1102/B/C modules operate with full functionality with the
National Instruments MIO, Lab-PC+, PCI-1200, DAQCard-1200, and
SCXI-1200 modules. You can use the PC-LPM-16 board and the
DAQCard-700 with the SCXI-1102/B/C, but these devices cannot scan
the module; they can only perform single-channel reads. You can
multiplex several SCXI-1102/B/C modules and other SCXI modules
into a single channel on the DAQ device, greatly increasing the number
of analog input signals that you can digitize.
Detailed specifications of the SCXI-1102/B/C modules are listed in
Appendix A, Specifications.
What You Need to Get Started
To set up and use your SCXI-1102/B/C module, you will need the
following items:
❑One of the following modules:
SCXI-1102
SCXI-1102B
SCXI-1102C
❑SCXI-1102/B/C User Manual
❑One of the following software packages and documentation:
ComponentWorks
LabVIEW for Macintosh
LabVIEW for Windows
LabWindows/CVI for Windows
Measure
NI-DAQ for Macintosh
NI-DAQ for PC Compatibles
VirtualBench
❑Your computer

Chapter 1 Introduction
© National Instruments Corporation 1-3 SCXI-1102/B/C User Manual
Software Programming Choices
You have several options to choose from when programming your
National Instruments DAQ and SCXI hardware. You can use National
Instruments application software, NI-DAQ, or register-level
programming.
National Instruments Application Software
ComponentWorks contains tools for data acquisition and instrument
control built on NI-DAQ driver software. ComponentWorks provides
a higher-level programming interface for building virtual instruments
through standard OLE controls and DLLs. With ComponentWorks, you
can use all of the configuration tools, resource management utilities,
and interactive control utilities included with NI-DAQ.
LabVIEW features interactive graphics, a state-of-the-art user
interface, and a powerful graphical programming language. The
LabVIEW Data Acquisition VI Library, a series of VIs for using
LabVIEW with National Instruments DAQ hardware, is included with
LabVIEW. The LabVIEW Data Acquisition VI Library is functionally
equivalent to NI-DAQ software.
LabWindows/CVI features interactive graphics, state-of-the-art user
interface, and uses the ANSI standard C programming language. The
LabWindows/CVI Data Acquisition Library, a series of functions for
using LabWindows/CVI with National Instruments DAQ hardware, is
included with the NI-DAQ software kit. The LabWindows/CVI Data
Acquisition Library is functionally equivalent to the NI-DAQ software.
VirtualBench features virtual instruments that combine DAQ products,
software, and your computer to create a stand-alone instrument with the
added benefit of the processing, display, and storage capabilities of
your computer. VirtualBench instruments load and save waveform data
to disk in the same forms that can be used in popular spreadsheet
programs and word processors.
Using ComponentWorks, LabVIEW, LabWindows/CVI, or
VirtualBench software will greatly reduce the development time
for your data acquisition and control application.

Chapter 1 Introduction
SCXI-1102/B/C User Manual 1-4
© National Instruments Corporation
NI-DAQ Driver Software
The NI-DAQ driver software is included at no charge with all National
Instruments DAQ hardware. NI-DAQ has an extensive library of
functions that you can call from your application programming
environment. These functions include routines for analog input
(A/D conversion), buffered data acquisition (high-speed A/D
conversion), analog output (D/A conversion), waveform generation,
digital I/O, counter/timer operations, SCXI, RTSI, self-calibration,
messaging, and acquiring data to extended memory.
NI-DAQ also internally addresses many of the complex issues between
the computer and the plug-in device, such as programming interrupts
and DMA controllers. NI-DAQ maintains a consistent software
interface among its different versions so that you can change platforms
with minimal modifications to your code. Figure 1-1 illustrates the
relationship between NI-DAQ and your National Instruments
application software.
Figure 1-1. The Relationship between the Programming Environment,
NI-DAQ, and Your Hardware
ComponentWorks,
LabVIEW,
LabWindows/CVI, or
VirtualBench
Conventional
Programming Environment
NI-DAQ
Driver Software
DAQ or
SCXI Hardware
Personal
Computer or
Workstation

Chapter 1 Introduction
© National Instruments Corporation 1-5 SCXI-1102/B/C User Manual
Register-Level Programming
The final option for programming any National Instruments DAQ
hardware is to write register-level software. Writing register-level
programming software can be very time-consuming and inefficient
and is not recommended.
Even if you are an experienced register-level programmer, consider
using NI-DAQ or other National Instruments application software to
program your National Instruments DAQ hardware. Using the
application software is easier than and as flexible as register-level
programming and can save weeks of development time.
Optional Equipment
National Instruments offers a variety of products to use with your
SCXI-1102/B/C module, as follows:
• Terminal blocks and 96-pin cables that allow you to attach input
signals to your module.
• SCXI process-current resistor kit
• Cables and cable assemblies, shielded and ribbon
For more specific information about these products, refer to your
National Instruments catalogue or call the office nearest you.

Chapter 1 Introduction
SCXI-1102/B/C User Manual 1-6
© National Instruments Corporation
Custom Cables
The following table summarizes the custom cable information.
Unpacking
Your SCXI-1102/B/C module is shipped in an antistatic package to
prevent electrostatic damage to the module. Electrostatic discharge can
damage several components on the module. To avoid such damage in
handling the module, take the following precautions:
• Ground yourself via a grounding strap or by holding a grounded
object.
• Touch the antistatic package to a metal part of your SCXI chassis
before removing the module from the package.
• Remove the module from the package and inspect the module for
loose components or any other sign of damage. Notify National
Instruments if the module appears damaged in any way. Do not
install a damaged module into your SCXI chassis.
•Never touch the exposed pins of connectors.
Signal
Connector SCXI–1102/B/C Connector Mating Connector Cable
Rear AMP Inc. (1-103310-0)
50-pin male ribbon
cable header
Electronic Products
Division/3M (3425-7650)
or T&B/Ansley Corp.
(609-5041CE) 50-position
polarized ribbon-socket
connector
Electronic Products
Division/3M (3365/50)
or T&B/Ansley Corp.
(171-50) 50-conductor,
28 AWG stranded
ribbon cable
Front Harting Electronik Inc.
(09-03-396-6921)
96-pin DIN C male
connector
AMP Inc. (535020;
right-angle pins) or Panduit
Corp. (100-096-434
straight-solder pins) 96-pin,
polarized, DIN C female
connector
N/A

© National Instruments Corporation 2-1 SCXI-1102/B/C User Manual
Chapter
2
Configuration and
Installation
This chapter describes how to configure your SCXI-1102/B/C jumper,
how to install current-loop receivers, and how to install your
SCXI-1102/B/C module into the SCXI chassis.
Module Configuration
The SCXI-1102/B/C contains one jumper, shown in Figure 2-1. Jumper
W1 connects a pullup resistor to the SERDATOUT signal on the rear
signal connector.
The remainder of the module configuration (gain, output signal
referencing, and so on) is software-programmable.

Chapter 2 Configuration and Installation
SCXI-1102/B/C User Manual 2-2
© National Instruments Corporation
Figure 2-1. SCXI-1102/B/C Module Parts Locator Diagram (1102 shown)
1 RCL24-RCL31
2 RCL14-RCL23 3 RCL8-RCL13
4 Assembly Number 5 RCL0-RCL7
6 Serial Number 7W1
23
6
5
4
1
7

Chapter 2 Configuration and Installation
© National Instruments Corporation 2-3 SCXI-1102/B/C User Manual
Digital Configuration
If you have a one-chassis system, you do not have to read this section.
You can skip to the next section, Analog Configuration.
Note: If nothing is cabled to the SCXI-1102/B/C module rear signal connector,
the position of jumper W1 is irrelevant.
The SCXI-1102/B/C modules have only one jumper—jumper W1—for
communication between the DAQ device and the SCXIbus, shown in
Table 2-1.
All SCXI modules have a jumper that corresponds to jumper W1 on the
SCXI-1102/B/C module. Refer to the user manuals of the other SCXI
modules in your system to determine the designator and settings of this
jumper. In the pullup position, this jumper connects a pullup resistor to
the SERDATOUT line. This pullup resistor pulls the SERDATOUT
line high when its open-collector driver goes to a high-impedance state.
The SERDATOUT line on the SCXI-1102/B/C module reads the
Module ID Register, the Status Register, and the EEPROM.
When using a single-chassis system, set the jumper in the pullup
position on the SCXI module cabled to the DAQ device. When using
multiple chassis, set the jumper to the pullup position on only one of the
SCXI modules cabled to the DAQ device.
Table 2-1. Jumper Settings for Digital Signal Connection
Jumper Description Configuration
Position PULLUP—Use this
setting for a single-chassis system
and for one cabled module in a
multi-chassis system. Connects a
2.2 kΩpullup resistor to the
SERDATOUT line. (factory
setting)
Position NO PULLUP—Use this
setting for additional chassis in a
multi-chassis system. No pullup
resistor is connected to the
SERDATOUT line.
W1
W1
PULLUP NO PULLUP
W1
PULLUP NO PULLUP

Chapter 2 Configuration and Installation
SCXI-1102/B/C User Manual 2-4
© National Instruments Corporation
If you want to change the W1 jumper setting, refer to Figure 2-2 as you
perform the following steps:
1. Ground yourself via a grounding strap or via a ground connected to
your SCXI chassis. Properly grounding yourself prevents damage
to your SCXI module from electrostatic discharge.
2. Remove the grounding screw of the top cover.
3. Snap out the top cover of the shield by placing a screwdriver in the
groove at the bottom of the module and pushing down on the
screwdriver.
4. Change the W1 jumper setting.
5. Reinstall the top cover and grounding screw.
Figure 2-2. Removing the SCXI Module Cover
Analog Configuration
Current-Loop Receivers
The SCXI-1102/B/C modules have pads for transforming individual
channels to current-to-voltage converters. National Instruments offers
an SCXI process-current pack of four 249 Ω, 0.1%, 5 ppm, 1/4 W
resistors. The reference designators for the current loop resistors have
Grounding
Screw
Top of Module
Front Connector
Removable Cover