National Instruments VXI-SC-1102 User Manual

VXI-SC-1102/B/C

User Manual

32-Channel Multiplexer Amplifier Submodules

August 1997 Edition

Part Number 321385B-01

© Copyright 1997 National Instruments Corporation. All rights reserved.

Internet Support

[e-mail]

E-mail: [e-mail]
FTP Site: ftp.natinst.com
Web Address: http://www.natinst.com

Bulletin Board Support

BBS United States: [phone]
BBS United Kingdom: 01635 551422
BBS France: 01 48 65 15 59

Fax-on-Demand Support

[phone]

Telephone Support (U.S.)

Tel: [phone]
Fax: [phone]

International Offices

Australia 03 9879 5166, Austria 0662 45 79 90 0, Belgium 02 757 00 20,
Canada (Ontario) 905 785 0085, Canada (Québec) 514 694 8521, Denmark 45 76 26 00,
Finland0972572511, France0148142424, Germany0897413130,
Hong Kong 2645 3186, Israel 03 5734815, Italy 02 413091, Japan 03 5472 2970,
Korea 02 596 7456, Mexico 5 520 2635, Netherlands 0348 433466, Norway 32 84 84 00,
Singapore 2265886, Spain 91 640 0085, Sweden 08 730 49 70, Switzerland 056 200 51 51,
Taiwan 02 377 1200, United Kingdom 01635 523545

National Instruments Corporate Headquarters

6504 Bridge Point Parkway Austin, TX 78730-5039 Tel: [phone]

Important Information

Warranty

The VXI-SC-1102,VXI-SC-1102B, and VXI-SC-1102C submodules 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 an d work manship, fo r a pe riod of 90 days from date of shipment , as evi denced
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 or typographical errors exist, National Instruments reserves
the right to make changes to subseq uent editio ns of th is do cum ent wi thout prio r not ice to ho lders of this edit ion. Th e
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.

XCEPT AS SPECIFIED HEREIN

E

SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE

USTOMER’S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL

C

NSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER

I

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

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.

ATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED, AND

, N

.

ATIONAL INSTRUMENTS

. N

. This limitation of the liability of National

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™, 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 perso nnel, and all traditi onal
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.

About This Manual

Organization of This Manual........................................................................................ix

Conventions Used in This Manual................................................................................x

National Instruments Documentation...........................................................................xi

Related Documentation.......................................... .......................................................xii

Customer Communication............................................................................................ xii

Chapter 1
Introduction

About the VXI-SC-1102/B/C .......................................................................................1-2

What You Need to Get Started .....................................................................................1-3

Software Programming Choices...................................................................................1-4

National Instruments Application Software................................................... 1-4

NI-DAQ Driver Software...............................................................................1-5

VXIplug&play Instrument Driver..................................................................1-6

Optional Equipment......................................................................................................1-6

Unpacking.....................................................................................................................1-7

Table

of

Contents

Chapter 2
Installation

Current-Loop Receivers................................................................................................2-3

Installing Your Hardware .............................................................................................2-4

Chapter 3
Signal Connections

Front Connector.............................................................. ..................................... .........3-1

Signal Descriptions........................................................................................3-3

Channel Input Signal Connections.................................................................3-3

Ground-Referencing Your Signals...................................................3-4

Cold-Junction Sensor Connection..................................................................3-6

©

National Instruments Corporation v VXI-SC-1102/B/C User Manual

Table of Contents

Chapter 4
Theory of Operation

Functional Overview....................................................................................................4-1

VXIbus Interface..........................................................................................................4-2

Digital Control Circuitry .............................................................................................. 4-2

Analog Circuitry........................................................................................................... 4-3

Analog Input Channels................................................................................... 4-3

Analog Output ................................................................................................4-4

Chapter 5
Calibration

Calibration Equipment Requirements .......................................................................... 5-1

Gain and Offset Calibration..........................................................................................5-2

Appendix A
Specifications

Appendix B
Calibration Sample Program

Sample Program for Calibration................................................................................... B-1

Appendix C
Customer Communication

Glossary

Index

Figures

Figure 1-1. VXI Signal Conditioning System ..........................................................1-1

Figure 1-2. The Relationship between the Programming Environment,

Your Instrument Driver, and Your VXI-DAQ Hardware..................... 1-6

Figure 2-1. VXI-SC-1102/B/C Parts Locator Diagram ........................................... 2-2

Figure 2-2. Bent and Trimmed Resistor................................................................... 2-3

VXI-SC-1102/B/C User Manual vi

©

National Instruments Corporation

Tables

Table of Contents

Figure 3-1. VXI-SC-1102/B/C 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 4-1. VXI-SC-1102/B/C Block Diagram........................................................4-1

Figure 5-1. Analog Bus Receptacle Pin Assignment ...............................................5-2

Table 3-1. Front Connector Signal Descriptions.....................................................3-3

©

National Instruments Corporation vii VXI-SC-1102/B/C User Manual

About

This

Manual

This manual describes the electrical and mechanical aspects of the
VXI-SC-1102 family and contains information concerning their
installation and operation. The VXI-SC-1102 family is a group of signal
conditioning submodules in the VXI-data acquisition (VXI-DAQ) line
of National Instruments products.

The VXI-SC-1102 family consists of the following submodules:

• VXI-SC-1102

• VXI-SC-1102B

• VXI-SC-1102C
Unless otherwise noted, VXI-SC-1102/B/C will hereafter refer to all

three submodules in the VXI-SC-1102 family.
The VXI-SC-1102/B/C submodules are designed for signal

conditioning of thermocouples, volt and millivolt sources, and
4–20 mA sources or 0–20 mA process-current sources. The
VXI-SC-1102/B/C submodules have 32 differential analog input
channels and one cold-junction sensor channel.

Organization of This Manual

The VXI-SC-1102/B/C User Manual is organized as follows:

• Chapter 1, Introduction, describes the VXI-SC-1102 family of
submodules, lists what you need to get started, optional software
and optional equipment, and explains how to unpack yo ur
VXI-SC-1102/B/C submodule.

• Chapter 2, Installation, describes how to install current-loop
receivers on your VXI-SC-1102/B/C and gives information about
installing your VXI-SC-1102/B/C into the VXI-SC-1000 carrier
module.

• Chapter 3, Signal Connections, describes the analog input signal
connections to the VXI-SC-1102/B/C submodule via the front
connector.

©

National Instruments Corporation ix VXI-SC-1102/B/C User Manual

About This Manual

• Chapter 4, Theory of Operation , contains a functional overview of
the VXI-SC-1102/B/C submodules and explains the operation of
each functional unit.

• Chapter 5, Calibration, discusses the calibration procedures for the
VXI-SC-1102/B/C submodules.

• Appendix A, Specifications, lists the specifications for the
VXI-SC-1102/B/C submodules.

• 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.

•The Glossary contains an alphabetical list and description of terms
used in this manual, including abbreviations, acronyms, metric
prefixes, mnemonics, symbols, and general data acquisition terms.

•The Index 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.

< > Angle brackets containing numbers separated by an ellipsis represent a

range of values associated with a port, b it, or signal name (f or example,
ACH<0..7> stands for the signals ACH0 through ACH7).

♦ The ♦ symbol indicates that the text following it applies only to specific

VXI-SC-1102 modules.
This icon to the left of bold italicized text denotes a note, which alerts

you to important information.

!

bold italic Bold italic text denotes a note, caution, or warning.

italic Italic text denotes emphasis, a cross reference, or an introduction to a

monospace Denotes text or characters that are to be literally input from the

VXI-SC-1102/B/C User Manual x

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.

This icon to the left of bold italicized text denotes a warning, which
advises you of precautions to take to avoid being electrically shocked.

key concept.

keyboard, sections of code, programming examples, and syntax

©

National Instruments Corporation

About This Manual

examples. This font is also used for the proper names of disk drives,
paths, directories, programs, subprograms, subroutines, device names,
functions, variables, file names, and extensions, and for statements and
comments taken from program code.

carrier module Refers to the VXI-SC-1000, which plugs directly into a VXI slot and on

which VXI-SC submodules are installed.
PC Refers to the IBM PC/XT, the IBM PC AT, and compatible computers.
SCMP Refers to the signal conditioning minipods in the VXI signal

conditioning system.
VXI-MIO module Refers to any of the National Instruments VXI-MIO series of plug-in

data acquisition devices.
VXI-SC submodule Refers to VXI signal conditioning hardware that installs onto the carrier

module.
VXI-SC-1102/B/C Refers to all submodules in the VXI-SC-1102 family, unless otherwise

submodules noted.

The Glossary lists abbreviations, acronyms, metric prefixes,

mnemonics, symbols, and terms.

National Instruments Documentation

The VXI-SC-1102/B/C User Manual is one piece of the documentation

set for your VXI-DAQ system. You could have any of several types of

documents, depending on the hardware and software in your system.

Use the different types of documents you have as follows:

• Your VXI-DAQ hardware documentation—These documents have
detailed information about the V XI-DAQ hardware that plugs into
or is connected to your VXIbus chassis. Use these documents for
hardware installation and configuration instructions, specification
information about your VXI-DAQ hardware, and application hi nts.

• Software documentation—You may have both application software
and driver software documentation. National Instruments
application software includes ComponentWorks, LabVIEW,
LabWindows
Instruments driver software includes NI-DAQ and VXIplug&play
instrument drivers. After you set up your hardware system, use
either your application or driver software documentation to help
you write your application. If you have a large, complicated
system, it is worthwhile to look through the software
documentation before you configure your hardware.

©

National Instruments Corporation xi VXI-SC-1102/B/C User Manual

®

/CVI, Measure, and VirtualBench. National

About This Manual

• Accessory installation guides or manuals—If you are using
accessory products, read the terminal block and cable assembly
installation guides or accessory device user manuals. They explain
how to physically connect the relevant pieces of the system.
Consult these guides when you are making your connections.

Related Documentation

The following document contains information you may find helpful:

• VXI-SC-1000 Carrier Module Installation Guide

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 to help 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.

VXI-SC-1102/B/C User Manual xii

©

National Instruments Corporation

Chapter

Introduction

This chapter describes the VXI-SC-1102 family of submodules; lists
what you need to get started, optional soft ware, and optional equipment;
and explains how to unpack your VXI-SC-1102/B/C submodule.

The VXI-SC-1102 family is part of the VXI signal conditioning system,
which consists of a carrier module and one or more VXI signal
conditioning submodules or filler panels as shown in Figure 1-1.

2

1

4

3

5

To VXIbus

Chassis

6

8

1

9

1 Analog Bus Receptacle
2 SCMPs
3 SCMP Socket

©

National Instruments Corporation 1-1 VXI-SC-1102/B/C User Manual

4 Address Switch
5 VXI-SC Subslot 1
6 VXI-SC Subslot 2

Figure 1-1.

7 VXI-SC Carrier Module
8 VXI-SC-1150 Submodule
9 VXI-SC Submodule

VXI Signal Conditioning System

7

Chapter 1 Introduction

The VXI-SC-1000 is a carrier module that installs into a slot in a
VXIbus chassis and is populated with one or two submodules. The
VXI-SC-1102/B/C is a submodule that installs into VXI-SC subslots on
a VXI-SC-1000 carrier module.

Your VXI-SC-1000 carrier module is shipped with a filler panel
installed in one of the submodule sites. This filler panel is necessary for
the attachment of the front panel, so you should leave it in place until
you are ready to install a VXI-SC submodule.

About the VXI-SC-1102/B/C

♦ The VXI-SC-1102 is a submodule for the signal conditioning of

thermocouples, low-bandwidth volt and millivolt sources, 4-20 mA current
sources, and 0-20 mA process-current sources. The VXI-SC-1102 has
32 differential analog input channels and one cold-junction sensor channel.
On each channel, the VXI-SC-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
VXI-SC-1102 inputs to a single output, which drives a single VXI-MIO
module channel.

♦ The VXI-SC-1102B is a submodule for the signal conditioning of

thermocouples, medium-bandwidth volt and millivolt sources, 4-20 mA
current sources, and 0-20 mA process-current sources. The
VXI-SC-1102B has 32 differential analog input channels and one
cold-junction sensor channel. On each channel, the VXI-SC-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
VXI-SC-1102B inputs to a single output, which drives a single VXI-MIO
module channel.

♦ The VXI-SC-1102C is a submodule for the signal conditioning of

thermocouples, high-bandwidth volt and millivolt sources, 4-20 mA
current sources, and 0-20 mA process-current sources. The
VXI-SC-1102C has 32 differential analog input channels and one
cold-junction sensor channel. On each channel, the VXI-SC-1102C has a
three-pole lowpass filter with a 10 kHz cutoff frequency. Each channel also
has an amplifier with a selectable gain of 1 o r 100. You can multiplex the
VXI-SC-1102C inputs to a single output, which drives a single VXI-MIO
module channel.

VXI-SC-1102/B/C User Manual 1-2

©

National Instruments Corporation

The VXI-SC-1102/B/C submodules operate with full functionality with
National Instruments VXI-MIO modules. You can multiplex several
VXI-SC-1102/B/C submodules and other VXI signal conditioning
submodules into a single channel on the VXI-MIO module, greatly
increasing the number of analog input signals that you can digitize.

You can also use National Instruments terminal blocks, which have
screw terminals to which you attach the input signals for the
VXI-SC-1102/B/C submodules. In addition, some of these terminal
blocks have a temperature sensor for thermocouple cold-junction
compensation (CJC). The VXI-SC-1102/B/C submodules multiplex
this cold-junction sensor with the 32 input channels during a hardware
scan. A National Instruments isothermal terminal block is
recommended for thermocouple applications.

Detailed specifications of the VXI-SC-1102/B/C submodules are listed
in Appendix A, Specifications.

What You Need to Get Started

To set up and use your VXI-SC-1102/B/C, you will need the following
items:

Chapter 1 Introduction

❑ One of the following submodules:

VXI-SC-1102
VXI-SC-1102B
VXI-SC-1102C

❑ VXI-SC-1102/B/C User Manual
❑ VXI-SC-1000 carrier module and documentation
❑ VXI-MIO module and documentation
❑ One of the following software packages and documentation:

ComponentWorks
LabVIEW for Windows
LabWindows/CVI for Windows
Measure
NI-DAQ for PC compatibles
VirtualBench
VXIplug&play instrument driver

❑ Your VXIbus system

©

National Instruments Corporation 1-3 VXI-SC-1102/B/C User Manual

Chapter 1 Introduction

Software Programming Choices

There are several options to choose from when programming your
National Instruments VXI-DAQ hardware. You can use LabVIEW,
LabWindows/CVI, ComponentWorks, VirtualBench, or other
application development environments with either NI-DAQ or
the VXIplug&play instrument driver. Both NI-DAQ and the
VXIplug&play instrument driver access the VXI-DAQ hardware
through the VISA driver software.

National Instruments Application Software

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 the NI-DAQ software.

LabWindows/CVI features interactive graphics, a 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 so ftware.

ComponentWorks contains tools for data acquisition and instrument
control built on NI-DAQ driver software. Compo nentWorks provi des a
higher-level programming interface for building virtual instruments
through standard OLE controls and DLLs. With ComponentWork s, you
can use all of the configuration tools, resource management utilities,
and interactive control utilities included with NI-DAQ.

VirtualBench features VIs 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 LabVIEW, LabWindows/CVI, ComponentWorks, or
VirtualBench software will greatly reduce the development time for
your data acquisition and control application.

VXI-SC-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 is not packaged with accessory
products. 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 has both high-level DAQ I/O functions for maximum ease
of use and low-level DAQ I/O functions for maximum flexibility and
performance. Examples of high-level functions are streaming data to
disk or acquiring a certain number of data points. An example of a
low-level function is writing directly to registers on the DAQ device.
NI-DAQ does not sacrifice the performance of National Instruments
DAQ devices because it lets multiple devices operate at their peak
performance.

NI-DAQ maintains a consistent software interface among its different
versions so that you can change platforms with minimal modifications
to your code.

Chapter 1 Introduction

©

National Instruments Corporation 1-5 VXI-SC-1102/B/C User Manual

Chapter 1 Introduction

VXI

plug&play

Instrument Driver

National Instruments distributes VXIplug&play instrument drivers free
of charge. VXIplug&play instrument drivers are one level above the
NI-DAQ device driver and contain high-level software functions whose
architecture is specified by the VXIplug&play Systems Alliance. The
VXIplug&play standards increase interoperability with other vendors,
and ensure that drivers are designed and presented in a consistent
fashion that facilitates ease of use. Refer to Figure 1-2 to see the
relationship between your VXI-DAQ hardware and your software.

Figure 1-2.

Optional Equipment

National Instruments offers a variety of products to use with your
VXI-SC-1102/B/C submodule, as follows:

• Terminal blocks and 96-pin cables that allow you to attach input
signals to your submodule

• SCXI Process Current Resistor Kit

ComponentWorks,

LabVIEW, LabWindows/CVI,

or VirtualBench

plug&play

VXI

Instrument Driver

NI-DAQ Driver Software

VISA

VXI-DAQ Hardware

The Relationship between the Programming Environment,

Your Instrument Driver, and Your VXI-DAQ Hardware

Other Application

Development Environments

For more specific information about these products, refer to your
National Instruments catalogue or call the office nearest you.

VXI-SC-1102/B/C User Manual 1-6

©

National Instruments Corporation

Unpacking

Chapter 1 Introduction

Your VXI-SC-1102/B/C submodule is shipped in an antistatic package
to prevent electrostatic damage to the submodule. Electrostatic
discharge can damage several components on the submodule. To avoid
such damage in handling the submodule, 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 VXIbus chassis
before removing the submodule from the package.

• Remove the submodule from the package and inspect the
submodule 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 submodule into your VXIbus
chassis.

• Never touch the exposed pins of connectors.

©

National Instruments Corporation 1-7 VXI-SC-1102/B/C User Manual

Chapter

Installation

2

This chapter describes how to install current-loop receivers on your
VXI-SC-1102/B/C and gives information about installing your
VXI-SC-1102/B/C into the VXI-SC-1000 carrier module.

Refer to Figure 2-1, VXI-SC-1102/B/C Parts Locator Diagram, for
information as you read the instructions in this chapter.

©

National Instruments Corporation 2-1 VXI-SC-1102/B/C User Manual

Chapter 2 Installation

2

3

1

4

1 Serial Number 2 Product Name 3 Assembly Number 4 RCLx Pads

Figure 2-1. VXI-SC-1102/B/C Parts Locator Diagram

VXI-SC-1102/B/C User Manual 2-2

©

National Instruments Corporation

Current-Loop Receivers

The VXI-SC-1102/B/C submodules have pads for transforming
individual channels to current-to-voltage converters. National
Instruments offers an SCXI Process Current Resistor Kit of four 249 Ω,

0.1%, 5 ppm, 1/4 W resistors. The reference designators for the current

loop resistors have the following format: for input channel x, the
resistor is RCLx. For example, the resistor for channel 28 is RCL28.

Caution: Before installing the resistors in your submodule, make sure that there are

!

no signals connected to your submodule front connector.

Install the resistors by performing the following steps:

1. Follow the instructions in the VXI-SC-1000 Carrier Module
Installation Guide to remove your VXI-SC-1102/B/C submodule
from the carrier assembly.

2. Bend and trim the resistor lead as shown in Figure 2-2. Be sure that
the resistor does not extend more than 0.65 in. above the surface of
the circuit board.

Chapter 2 Installation

Figure 2-2.

3. Insert the resistor into the appropriate pa d, labeled RCLx.

4. Solder the leads to the pad on the bottom side of the module.

5. Follow the instructions in the VXI-SC-1000 Carrier Module
Installation Guide to replace the VXI-SC-1102/B/C submodule in
the carrier assembly.

©

National Instruments Corporation 2-3 VXI-SC-1102/B/C User Manual

Bent and Trimmed Resistor

Chapter 2 Installation

Installing Your Hardware

Follow the instructions in the VXI-SC-1000 Carrier Module Installation
Guide to install the assembled VXI-SC carrier module in the VXIbus

chassis.

VXI-SC-1102/B/C User Manual 2-4

©

National Instruments Corporation

Chapter

Signal Connections

This chapter describes the analog input signal connections to the
VXI-SC-1102/B/C submodule via the front connector.

Caution:

!

Front Connector

Static electricity is a major cause of component failure. To prevent damage
to the electrical components in the module, observe antistatic techniques
whenever removing a module from the chassis or whenever working on a
module.

Figure 3-1 shows the pin assignments for the VXI-SC-1102/B/C
submodule front connector.

3

©

National Instruments Corporation 3-1 VXI-SC-1102/B/C User Manual

Chapter 3 Signal Connections

CGND

NC
NC
NC
NC
NC
NC
NC

CGND

NC
NC
NC
NC
NC
NC
NC

CGND

NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

CGND

CJSENSOR
CJSENSOR

CGND

+5 V

32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10

A

CH0­CH1­CH2­CH3­CH4­CH5­CH6­CH7­CH8-

CH9­CH10­CH11­CH12­CH13­CH14­CH15­CH16­CH17­CH18­CH19­CH20­CH21­CH22-

9
8
7
6
5
4
3
2
1

CH23­CH24­CH25­CH26­CH27­CH28­CH29­CH30­CH31-

32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10

B

CH0+
CH1+
CH2+
CH3+
CH4+
CH5+
CH6+
CH7+
CH8+

CH9+
CH10+
CH11+
CH12+
CH13+
CH14+
CH15+
CH16+
CH17+
CH18+
CH19+
CH20+
CH21+
CH22+

9
8
7
6
5
4
3
2
1

CH23+
CH24+
CH25+
CH26+
CH27+
CH28+
CH29+
CH30+
CH31+

C

32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10

9
8
7
6
5
4
3
2
1

Figure 3-1. VXI-SC-1102/B/C Front Connector Pin Assignments

VXI-SC-1102/B/C User Manual 3-2

©

National Instruments Corporation

Signal Descriptions

Chapter 3 Signal Connections

Table 3-1.

Pin Signal Name Description

A1 +5 V +5 VDC Source—Powers the

A2, A5, A16,
A24, A32

A3, A4 CJSENSOR Cold-Junction Temperature

B1–B32 CH31-

C1–C32 CH31+

All other pins are not connected.

Front Connector Signal Descriptions

temperature sensor on the terminal
block. 0.2 mA of source not
protected.

CGND Chassis Ground—Tied to the

VXIbus chassis.

Sensor Input—Connects to the
temperature sensor of the terminal
block.

Negative Input Channels 31–0
through
CH0-

through
CH0+

—Negative side of differential

input channels.

Positive Input Channels 31–0

—Positive side of differential

input channels.

Channel Input Signal Connections

The signal terminals for the positive input channels are located in
column C of the connector. The signal terminal for each corresponding
negative input channel is located in column B of the connector. Each
input goes to a separate filter and amplifier that is multiplexed to the
module output buffer. The terminal block temperature sensor output—
connected to pins A3 and A4 (CJSENSOR)—is also filtered and
multiplexed to the module output buffer.

The differential input signal range of a VXI-SC-1102/B/C input channel
is ±10 V/G, where G is the gain selected on the VXI-SC-1102/B/C input
channel. This differential input range is the maximum measurable
voltage difference between the positive and negative channel inputs.
The common-mode input signal range of a VXI-SC-1102/B/C input

©

National Instruments Corporation 3-3 VXI-SC-1102/B/C User Manual

Chapter 3 Signal Connections

Warning: Exceeding the input damage level (±42 VAC peak or VDC between input

channels and chassis ground) can damage the VXI-SC-1102/B/C
submodule, the VXIbus, and the VXI-MIO module. National Instruments
is

NOT

Applying a voltage greater than ±42 VAC peak or VDC to the
VXI-SC-1102/B/C is an electrical shock hazard. National Instruments is

NOT

application.

Note: Exceeding the differential or common-mode input channel ranges results

in a distorted signal measurement.

channel is ±11 V. This common-mode input range for either positive or
negative channel input is the maximum input voltage (relative to
CGND) that will result in a valid measurement. Each channel includes
input protection circuitry to withstand the accidental application of
voltages up to ±42 VAC peak or VDC.

liable for any injuries resulting from such signal connections.

liable for any damages or injuries resulting from such voltage

Ground-Referencing Your Signals

Your input signals can be either ground-referenced, as shown in
Figure 3-2, or floating, as shown in Figure 3-3. Before you connect
your thermocouple or any other signal, determine whether it is fl oatin g
or ground-referenced. If it is a floating signal, you must ground­reference the signal in one of two ways. You can connect the negative
channel input to chassis ground as shown in Figure 3-3 or you can use
the clamping resistors on a VXI-TB Series terminal block. The VXI-TB
Series terminal block may also have a resistor pack for pulling up the
positive inputs for open-thermocouple detection. Consult the terminal
block installation guide for details.

Do not ground signals that are already ground -referenced; doing so will
result in a ground loop, which adversely affects your measurement
accuracy.

VXI-SC-1102/B/C User Manual 3-4

©

National Instruments Corporation

Chapter 3 Signal Connections

CH0 +
CH0 -

+

V

diff

-

+

V

cm

-

CH1 +

CH1 -

Connector

Front Signal

+

-

+

-

VXI-SC-1102/B/C

Figure 3-2. Ground-Referenced Signal Connection

©

National Instruments Corporation 3-5 VXI-SC-1102/B/C User Manual

Chapter 3 Signal Connections

CH0 +
CH0 -

Floating

Signal

Make this connection to

ground reference the signal.

+

V

s

-

Reference to

Chassis Ground

CH1 +
CH1 -

Front Signal

CGND

Figure 3-3. Floating Signal Connection Referenced to Chassis Ground

Cold-Junction Sensor Connection

Pins A3 and A4 (CJSENSOR) connect the temperature sensor located
on the National Instruments VXI-TB Series terminal block to the
VXI-SC-1102/B/C. The CJSENSOR signal is measured relative to
CGND. Pins A3 and A4 are connected together within the
VXI-SC-1102/B/C so the position of the MTEMP/DTEMP switch on
the VXI-TB Series terminal block does not matter. The input is
overvoltage-protected to 15 VDC with the power on and off.

+

-

+

-

Connector

VXI-SC-1102/B/C

Caution: Exceeding the overvoltage protection on the CJSENSOR input can damage

!

the VXI-SC-1102/B/C submodule, the VXIbus, and the VXI-MIO board.
National Instruments is

NOT

from such signal connections.

VXI-SC-1102/B/C User Manual 3-6

liable for any damages or injuries resulting

©

National Instruments Corporation

Chapter

Theory of Operation

This chapter contains a functional overview of the VXI-SC-1102/B/C
submodules and explains the operation of each functional unit.

Functional Overview

The block diagram in Figure 4-1 illustrates the key functional
components of the VXI-SC-1102/B/C submodules.

CH 0 +

CH 0 –

+

Inst.
Amp

–

Input Protection

and Lowpass Filter

Gain 0

Lowpass

Filter

Buffer

4

Buffer

Mux

32-to-1 Mux

CH 31+

CH 31 –

Front Signal Connector

CJSENSOR

©

National Instruments Corporation 4-1 VXI-SC-1102/B/C User Manual

+

Inst.
Amp

–

Input Protection

and Lowpass Filter

Input Protection

and Lowpass Filter

Gain 31

Lowpass

Filter

Lowpass

Filter

Buffer

Buffer

Figure 4-1.

Switch
Switch

Gain

Register

Calibration EEPROM

Digital

Control

VXI-SC-1102/B/C Block Diagram

Analog Bus +
Analog Bus -

Connector to Carrier Module

Chapter 4 Theory of Operation

The major components of the VXI-SC-1102/B/C submodules are as
follows:

• VXIbus interface

• Digital control circuitry

• Analog circuitry
The VXI-SC-1102/B/C submodules consist of 32 multiplexed input

channels, each with a software-programmable gain of 1 or 100. Each
input channel has its own lowpass filter. The VXI-SC-1102/B/C
submodules also have digital control circuitry for automatic control of
channel scanning, temperature sensor selection, and gain selection.

VXIbus Interface

The VXI-DAQ module controls the VXI-SC-1102/B/C over the
VXIbus. The VXI-SC-1000 carrier module serves as an interface from
the VXI-SC-1102/B/C submodules to the VXIbus.

Digital Control Circuitry

The digital control circuitry consists of the address handler and the
following registers: Module ID, Configuration, Status, EEPROM, Gain,
and Channel. The address handler controls which re gister is being
addressed. The Module ID Register contains a code unique to each type
of VXI-SC-1102/B/C submodule:

♦ VXI-SC-1102—The Module ID is 42 decimal.
♦ VXI-SC-1102B—The Module ID is 43 decimal.
♦ VXI-SC-1102C—The Module ID is 63 decimal.

The Configuration Register configures the VXI-SC-1102/B/C
submodules for the desired scanning mode and connection to the rear
signal connector. The Status Register indicates whether the input
channels have settled after a change in the gains. The EEPROM
Register is the address for interfacing with the submodule’s EEPROM,
which contains calibration information. The Gain Register selects
between gains of 1 or 100 for each of the 32 channels. The Channel
Register selects a channel for a single measurement or a start channel
for a scan. Refer to Software Programming Choices in Chapter 1,

VXI-SC-1102/B/C User Manual 4-2

©

National Instruments Corporation

Introduction, of this manual to learn about options for programming the
control circuitry.

Analog Circuitry

The analog circuitry per channel consists of a lowpass filter and an
amplifier with a software-selectable gain of 1 or 100. The CJSENSOR
channel also has a buffered lowpass filter but has no amplifier. The
channels and CJSENSOR are multiplexed to a single output buffer.

Analog Input Channels

Each of the 32 analog input channels drives a separate amplifier with a
programmable gain of 1 or 100. Then the signal passes through a
three-pole lowpass filter.

Note: Because of the 2 Hz bandwidth of the VXI-SC-1102 input channels, you

must wait approximately 3 s after changing the gains before the channels
settle and you can take an accurate measurement. NI-DAQ automatically
reads the Status Register to determine when the module output has settled.
This time is approximately 100 ms and 1 ms for the VXI-SC-1102B and
VXI-SC-1102C, respectively.

Chapter 4 Theory of Operation

The temperature sensor consists of a thermistor located on a National
Instruments VXI terminal block. The temperature sensor is for
cold-junction compensation of thermocouples. The CJSENSOR
channel also passes through a 2 Hz lowpass filter to reject unwanted
noise. Along with the other 32 input channels, the CJSENSOR is
multiplexed to the output buffer, wh ere it can be read by the VXI-MIO
module.

For a measurement accuracy of 0.012% of full scale, the minimum scan
interval is 3 µs. This is the smallest interval in which you can switch
between analog channels on the submodule and still measure accurate
voltages. The 3 µs scan interval gives you a maximum sampling rate o f
333 kHz. Because each VXI-SC-1102/B/C channel contains a lowpass
filter, the 333 kHz sample rate allows you to sample multiple channels
without undersampling any channel.

©

National Instruments Corporation 4-3 VXI-SC-1102/B/C User Manual

Chapter 4 Theory of Operation

Analog Output

The 32 input channels and the CJSENSOR are multiplexed into one
output. This output is passed to the VXI-SC-1000 carrier module, where
it is connected to the analog bus for measurement by a VXI-MIO
module.

VXI-SC-1102/B/C User Manual 4-4

©

National Instruments Corporation

Chapter

Calibration

This chapter discusses the calibration procedures for the
VXI-SC-1102/B/C submodules.

Using the procedure described in this chapter, you will be able to
calculate the gain error and voltage offset on a per channel per gain
basis. You can store these constants in the onboard EEPROM for
future use and for automatic calibration when you are using National
Instruments software. The VXI-SC-1102/B/C submodules come from
the factory with factory-determined calibration constants in the
EEPROM. However, National Instruments recommends that you
recalibrate your VXI-SC-1102/B/C at least once per year or when you
operate the submodule outside the 20° to 30° C temperature range.

In order to calibrate the VXI-SC-1102/B/C, you will need to apply
precision voltages to the channel inputs and/or ground the channel
inputs.

Calibration Equipment Requirements

5

According to standard practice, the equipment you use to calibrate the
VXI-SC-1102/B/C should be 10 times as accurate as the
VXI-SC-1102/B/C submodule itself. Calibration equipment with four
times the accuracy of the VXI-SC-1102/B/C is generally considered
acceptable. To calibrate the VXI-SC-1102/B/C submodules, you need a
voltmeter with the following specifications:

• Accuracy ±6 ppm standard reading
±15 ppm sufficient reading

• Range ±10 V

• Resolution 8.5 digits

A multiranging 8.5-digit digital multimeter (DMM) can perform the
necessary calibrations.

To make sure that the DMM does not introdu ce an additional offset, you
can determine the offset error of the DMM by shorting its leads together

©

National Instruments Corporation 5-1 VXI-SC-1102/B/C User Manual

Chapter 5 Calibration

and reading the measured value. This value, the DMM offset, must be
subtracted from all subsequent measurements.

Measure the submodule’s output at the analog bus receptacle
(see Figure 1-1 for the location of this receptacle). Refer to Figure 5-1
to connect the positive DMM input to MUX+ and the negative DMM input
to MUX-.

MUX+ MUX- CAL- CAL+

MUX- MUX+ CAL+ CAL-

Figure 5-1. Analog Bus Receptacle Pin Assignment

Gain and Offset Calibration

To determine the offset and gain calibration factors of the
VXI-SC-1102/B/C submodules for a given gain, perform the following
steps for a two-point calibration. For two-point calibration, it is best to
use input voltages that correspond to the signal range of interest. For
example, to measure bipolar voltages over the submodule’s full input
range, choose –9.9 V/G (negative full-scale) and +9.9 V/G (positive
full-scale) as your two input voltages.

1. Select the desired channel. Set the channel gain to the desired gain.

2. Apply the input for the first calibration point. To select negative
full scale as the calibration point, apply –9.9 V/G for an input
voltage.

a. Apply the input voltage to the channel selected in Step 1.

VXI-SC-1102/B/C User Manual 5-2

©

National Instruments Corporation

Chapter 5 Calibration

Note: To make one of yo ur calibrat ion po int s the zero point, connect the positive

and negative channel leads to one of the chassis ground pins on the front
connector or terminal block.

b. Measure the input voltage with the DMM. Call the measured

voltage

input1.

Note: If you are using a calibrator that supplies accurate volt ages, you can simply

use the known applied voltage for

input1 instead of measuring.

c. Measure the module output at the analog bus receptacle with

the DMM. Call the measured voltage

output1

.

3. Repeat Step 2, applying the input for the second calibration point.
Call the measured voltages

input2 and output2. To select

positive full scale as the calibration point, repeat Step 2 and apply
+9.9 V/G.

4. You now have two pairs of voltages (

(

input2, output2

). Each pair consists of an input voltage and an

input1, output1

) and

output voltage.

5. Convert the output voltages from volt units to your VXI-MIO
module binary unit. You must take into consideration the polarity
of your VXI-MIO module, its resolution (12 bits or 16 bits), and
gain. For example, if you are using the 12-bit VXI-MIO-64E-1 in
bipolar mode with the gain set to G

, your output voltages for the

MIO

autozeroing option will be represented in binary units as given by
the following formula:

Binary

=

Output

----------------- ­5 V

12

2

•

•

G

MIO

For other VXI-MIO modules, refer to the device user manual to
determine the appropriate formula.

6. You now have a new set of pairs referred to as voltage binary pairs

input1, bin_output1) and (input2, bin_output2). Pass these

(
pairs to the

SCXI_Cal_Constants function or VI as described in

your software user documentation.

Note: When you use 0 V and positive full-scale for your two calibration points,

you eliminate the error at 0 V and at positive full-scale voltage. However,
because of nonlinearity, the error at the negative full-scale voltage will be
two times the nonlinearity error. This is also true for the positive full-scale
voltage if you use the negative full-scale voltage and 0 V as your two
calibration points.

©

National Instruments Corporation 5-3 VXI-SC-1102/B/C User Manual

Chapter 5 Calibration

When you make a measurement using LabVIEW, ComponentWorks, or
VirtualBench, the driver automatically uses the calibration constants to
correct the measured voltages.

When you use application development environments other than
LabVIEW, ComponentWorks, or VirtualBench, you have the option to
apply the calibration constants to measured voltages through the
NI-DAQ API.

Refer to Appendix B, Calibration Sample Program, for an example of
a calibration program for your submodule.

VXI-SC-1102/B/C User Manual 5-4

©

National Instruments Corporation

Appendix

Specifications

This appendix lists the specifications for the VXI-SC-1102/B/C
submodules. These specifications are typical at 25° C unless
otherwise noted.

VXI-SC-1102/B/C

Analog Input

Input Characteristics

Number of channels............................32 differential

Input signal ranges................................±100 mV (gain = 100) or

Max working voltage

(signal + common mode) ....................Each input should remain

A

±10 V (gain = 1)

within ±10 V of CGND

Input damage level ...............................±42 VAC peak or VDC

Inputs protected............................CH<0..31>, CJSENSOR

Transfer Characteristics

Nonlinearity........................................0.005% FSR

Offset error

Gain = 1

After calibration .................... 300 µV max

Before calibration..................600 µV

Gain = 100

After calibration .................... 15 µV max

Before calibration..................100 µV

©

National Instruments Corporation A-1 VXI-SC-1102/B/C User Manual

Appendix A Specifications

Gain error

Gain = 1

After calibration.................... 0.015% of reading max

Before calibration ................. 0.04% of reading

Gain = 100

After calibration.................... 0.02% of reading max

Before calibration ................. 0.1% of reading

Amplifier Characteristics

Input impedance

Normal powered on ..................... >1 GΩ

Powered off................................. 10 kΩ

Overload ...................................... 10 kΩ

Input bias current...................................±0.5 nA

Input offset current................................±1.0 nA

CMRR

50 to 60 Hz, either gain 110 dB 90 dB 90 dB
0 Hz, gain 1 75 dB min 75 dB min 75 dB min
0 Hz, gain 100 100 dB min 100 dB min 100 dB min

Output range ..........................................±10 V

Output impedance ..............................0.1 Ω

Dynamic Characteristics

Bandwidth (-3 dB) ............................. 2 Hz (1102)

Scan interval (per channel, any gain)

0.012% ........................................ 3 µs

0.0061% ......................................10 µs

VXI-SC-1102/B/C User Manual A-2

1102 1102B 1102C

200 Hz (1102B)
10 kHz (1102C)

©

National Instruments Corporation

Filters

Appendix A Specifications

System noise (related to input)

1102 1102B 1102C

Gain = 1 50 µVrms 50 µVrms 70 µVrms
Gain = 100 5 µVrms 5 µVrms 10 µVrms

Cutoff frequency (–3 dB)....................2 Hz (1102)

200 Hz (1102B)
10 kHz (1102C)

NMR (60 Hz)......................................40 dB

Step response (either gain)

1102 1102B 1102C

To 0.1% 1 s 10 ms 200 µs
To 0.01% 10 s 100 ms 1 ms

Stability

Recommended warm-up time..............20 min.

Offset temperature coefficient

Gain = 1 .......................................20 µV/°C

Gain = 100 ...................................1 µV/°C

Gain temperature coefficient ............... 10 ppm/ °C

Physical

Dimensions.........................................115 by 273 mm

(4.54 by 10.75 in.)

I/O connector......................................50-pin male ribbon cable

rear connector
96-pin male DIN C front
connector

©

National Instruments Corporation A-3 VXI-SC-1102/B/C User Manual

Appendix A Specifications

Environment

Operating temperature ........................ 0° to 50° C

Storage temperature ........................... –55° to 150° C

Relative humidity............................... 5% to 90% noncondensing

Power Requirements

5 V supply .......................................... 15 mA max

±15 V supply (regulated

from ±24 V supply)............................ 150 mA max

VXI-SC-1102/B/C User Manual A-4

©

National Instruments Corporation

Appendix

Calibration Sample Program

This chapter contains a sample program to help you calibrate your
submodule.

B

Sample Program for Calibration

The following sample C program will help you calibrate the
VXI-SC-1102/B/C submodules. The calibration constants are stored
only in NI-DAQ memory. You must enter the (input, output) voltage
pairs read by a DMM by hand. Before running the sample program
below, you must run the NI-DAQ Configuration Utility to configure the
VXI-SC chassis and to configure the DAQ device that will
communicate with the VXI-SC-1102/B/C.

The following sample program is written to work for a DAQ device,
such as the VXI-MIO-64E-1, with a 5 V full-scale input:

#include <stdio.h>
#include <math.h>
#include <dataacq.h>

#define MIO_FULL_SCALE 5.0 /* valid for VXI-MIO-64E-1 */
#define N_VXI_SC_SLOTS 24
#define NIDAQMEM 0
#define ALL -1

int
enterInt (char *prompt)
{

short

ret;

int

value;

©

National Instruments Corporation B-1 VXI-SC-1102/B/C User Manual

Appendix B Calibration Sample Program

do
{

fputs(prompt, stdout);
fflush(stdin);

ret = scanf("%d", &value);
} while (!ret);
return (value);

}

double
enterFloat (char *prompt)
{

short

ret;
double

value;

do
{

fputs(prompt, stdout);

fflush(stdin);

ret = scanf("%lf", &value);
} while (!ret);
return (value);

}

void
main()
{

int

vxiChassisID,
commPath,
moduleSlot, /* slot of module to calibrate */
moduleChan;

short

dummyRangeCode = 0,
dummyDAQboard,
dummyDAQchan = 0,
dummyDAQgain = 1,
dummyDAQrange; /* These dummy variables would be

VXI-SC-1102/B/C User Manual B-2

used if the measurement actually
came from a DAQ board and not an
external DMM. */

©

National Instruments Corporation

Appendix B Calibration Sample Program

double

scale,
gain,
vInput1,
vOutput1,
vInput2,
vOutput2,
binOutput1,
binOutput2,
binOffset,
gainerr,
offset;

do

{

vxiChassisID = enterInt ("\nEnter chassis ID of the V XI-SC chassis:");
} while (vxiChassisID < 1);
do
{

moduleSlot = enterInt ("Enter slot of the VXI-SC-1102: ");
} while (moduleSlot < 1 || N_VXI_SC_SLOTS < moduleSlot);
do
{

commPath = enterInt ("Enter device number of the DAQ board"

"controlling the chassis: ");
} while (commPath < 0);
dummyDAQboard = commPath;

dummyDAQrange = MIO_FULL_SCALE / dummyDAQgain;
scale = pow(2.0, 12.0) * dummyDAQgain / 10;

/* factor for converting to format

of 12-bit bipolar DAQ board */

SCXI_Reset (vxiChassisID, moduleSlot);

SCXI_Single_Chan_Setup (vxiChassisID, moduleSlot, 0, dummyDAQboard);

/* This is necessary only so that

SCXI_Change_Chan won't return

an error. */
for (gain = 1; gain <= 100; gain = gain + 99)
{

SCXI_Set_Gain (vxiChassisID, moduleSlot, ALL, gain);

/* Set the gain on all channels. */

for (moduleChan = 0; moduleChan < 32; moduleChan++)

©

National Instruments Corporation B-3 VXI-SC-1102/B/C User Manual

Appendix B Calibration Sample Program

{

SCXI_Change_Chan (vxiChassisID, moduleSlot, moduleChan);

printf("Apply input voltage for point 1, channel %d, gain %.0f.\n"

moduleChan, gain);,

vInput1 = enterFloat ("Enter VXI-SC-1102 input voltage: ");

vOutput1 = enterFloat ("Enter VXI-SC-1102 output voltage: ");

printf("Apply input voltage for point 2, channel %d, gain

%.0f.\n",moduleChan, gain);

vInput2 = enterFloat ("Enter VXI-SC-1102 input voltage: ");

vOutput2 = enterFloat ("Enter VXI-SC-1102 output voltage: ");

binOutput1= vOutput1*scale;
binOutput2= vOutput2*scale; /* Convert to DAQ board's format. */

SCXI_Cal_Constants (vxiChassisID, moduleSlot, moduleChan,

offset = binOffset/scale; /* Convert from DAQ board format. */

printf("Calculated offset %f V, gain ratio (actual/ideal) %f"

"and stored in NI-DAQ memory.\n\n", offset, gainerr);

}

}

}

/* Select the channel. */

/* User enters vInput1. */

/* User enters vOutput1. */

/* User enters vInput2. */

/* User enters vOutput2. */

2, NIDAQMEM, dummyRangeCode, gain,
dummyDAQboard, dummyDAQchan, dummyDAQgain, 1,
vInput1, binOutput1, vInput2, binOutput2,
&binOffset, &gainerr);

/* Calculate offset & gain error. */

VXI-SC-1102/B/C User Manual B-4

©

National Instruments Corporation

Appendix

Customer Communication

For your convenience, this appendix contains forms to help you gather the information necessary to
help us solve your technical problems and a form you can use to comment on the product
documentation. When you contact us, we need the information on the Technical Support Form and the
configuration form, if your manual contains one, about your system configuration to answer your
questions as quickly as possible.

National Instruments has technical assistance through electronic, fax, and telephone systems to
quickly provide the information you need. Our electronic services include a bulletin board service,
an FTP site, a fax-on-demand system, and e-mail support. If you have a hardware or software
problem, first try the electronic support systems. If the information available on these systems
does not answer your questions, we offer fax and telephon e support through our technical sup port
centers, which are staffed by applications engineers.

C

Electronic Services

Bulletin Board Support

National Instruments has BBS and FTP sites dedicated for 24-hour support with a collection of files
and documents to answer most common customer questions. From these sites, you can also download
the latest instrument drivers, updates, and example programs. For recorded instructions on how to use
the bulletin board and FTP services and for BBS automated information, call [phone]. You can
access these services at:

United States: [phone]

Up to 14,400 baud, 8 data bits, 1 stop bit, no parity

United Kingdom: 01635 551422

Up to 9,600 baud, 8 data bits, 1 stop bit, no parity

France: 01 48 65 15 59

Up to 9,600 baud, 8 data bits, 1 stop bit, no parity

FTP Support

To access our FTP site, log on to our Internet host,
Internet address, such as
documents are located in the

©

National Instruments Corporation C-1 VXI-SC-1102/B/C User Manual

[e-mail], as your password. The support files and

/support directories.

ftp.natinst.com, as anonymous and use your

Fax-on-Demand Support

Fax-on-Demand is a 24-hour information retrieval system containing a library of documents on a wide
range of technical information. You can access Fax-on-Demand from a touch-tone telephone at
[phone].

E-Mail Support (currently U.S. only

You can submit technical support questions to the applications engineering team through e-mail at the
Internet address listed below. Remember to include your name, address, and phone number so we can
contact you with solutions and suggestions.

[e-mail]

)

Telephone and Fax Support

National Instruments has branch offices all over the world. Use the list below to find the technical
support number for your country. If there is no National Instruments office in your country, contact the
source from which you purchased your software to obtain support.

Telephone Fax

Australia 03 9879 5166 03 9879 6277
Austria 0662 45 79 90 0 0662 45 79 90 19
Belgium 02 757 00 20 02 757 03 11
Canada (Ontario) 905 785 0085 905 785 0086
Canada (Quebec) 514 694 8521 514 694 4399
Denmark 45 76 26 00 45 76 26 02
Finland 09 725 725 11 09 725 725 55
France 01 48 14 24 24 01 48 14 24 14
Germany 089 741 31 30 089 714 60 35
Hong Kong 2645 3186 2686 8505
Israel 03 5734815 03 5734816
Italy 02 413091 02 41309215
Japan 03 5472 2970 03 5472 2977
Korea 0 2 596 7456 02 596 7455
Mexico 5 520 2635 5 520 3282
Netherlands 0348 433466 0348 430673
Norway 32 84 84 00 32 84 86 00
Singapore 2265886 2265887
Spain 91 640 0085 91 640 0533
Sweden 08 730 49 70 08 730 43 70
Switzerland 056 200 51 51 056 200 51 55
Taiwan 02 377 1200 02 737 4644
United Kingdom 01635 523545 01635 523154
United States 512 795 8248 512 794 5678

Technical Support Form

Photocopy this form and update it each time you make changes to your software or hardware, and use
the completed copy of this form as a reference for your current configuration. Completing this form
accurately before contacting National Instruments for technical support helps our applications
engineers answer your questions more efficiently.

If you are using any National Instruments hardware or software products related to this problem,
include the configuration forms from their user manuals. Include additional pages if necessary.

Name ____________________________________________________________ ______________
Company _______________________________________________________________________
Address ________________________________________________________________________

_______________________________________________________________________________
Fax ( ___ )___________________ Phone ( ___ ) _______________________________________
Computer brand ________________ Model ________________ Processor___________________
Operating system (include version number) ____________________________________________
Clock speed ______MHz RAM _____MB Display adapter __________________________
Mouse ___yes ___no Other adapters installed _________________________ ___ ___________
Hard disk capacity _____MB Brand _____________________________________________
Instruments used _________________________________________________________________

_______________________________________________________________________________
National Instruments hardware product model __________ Revision ______________________
Configuration _______________________________________________________________ ____
National Instruments software product ____________________________ Version ____________
Configuration ___________________________________________________________________
The problem is: __________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________
List any error messages: ___________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________
The following steps reproduce the problem:____________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

VXI-SC-1102/B/C Submodule Hardware and Software
Configuration Form

Record the settings and revisions of your hardware and software on the line to the right of each item.
Complete a new copy of this form each time you revise your software or hardware configuration, and
use this form as a reference for your current configuration. Completing this form accurately before
contacting National Instruments for technical support helps our applications engineers answer your
questions more efficiently.

National Instruments Products

Application Software and Version _____________________________________ _______________

Other Products

Computer make and model _________________________________________________________
Microprocessor ___________________________________ ________________________________
Clock frequency or speed ___________________________________________________________
Type of video board installed ________________________________________________ ________
Operating system version ___________________________________________________________
Operating system mode ____________________________________________________________
Programming language ____________________________________________________________
Programming language version ______________________________________________________
Other boards in system ____________________________________ _________________________
Base I/O address of other boards _____________________________________________________
DMA channels of other boards ______________________ ________________________________
Interrupt level of other boards _______________________________________________________

Documentation Comment Form

National Instruments encourages you to comment on the documentation supplied with our products.
This information helps us provide quality products to meet your needs.

Title: VXI-SC-1102/B/C User Manual
Edition Date: August 1997
Part Number: 321385B-01

Please comment on the completeness, clarity, and organization of the manual.

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

If you find errors in the manual, please record the page numbers and describe the errors.

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

Thank you for your help.
Name _________________________________________________________________________
Title __________________________________________________________________________
Company _______________________________________________________________________
Address _________________________________________ _______________________________

_________________________________________ ______________________________________
Phone ( ___ )__________________________ Fax ( ___ ) ________ ________________________

Mail to: Technical Publications Fax to: Technical Publications

National Instruments Corporation National Instruments Corporation
6504 Bridge Point Parkway [phone]
Austin, TX 78730-5039

Prefix Meaning Value

Glossary

p- pico- 10
n- nano- 10
µ-micro-10

m- milli- 10

k- kilo- 10

M- mega- 10

G- giga- 10

Numbers/Symbols

+5 V +5 volt signal

° degrees
Ω ohms

% percent
± plus or minus

–12

–9

–6

–3

3

6

9

A

AC alternating current
A/D analog-to-digital
ADC analog-to-digital converter–an electronic device, often an integrated

circuit, that converts an analog voltage to a digital number

©

National Instruments Corporation G-1 VXI-SC-1102/B/C User Manual

Glossary

amplification a type of signal conditioning that improves accuracy in the resulting

digitized signal and reduces noise

API application programming interface

B

bus the group of conductors that interconnect individual circuitry in a

computer. Typically, a bus is the expansion vehicle to which I/O or
other devices are connected. Examples of PC buses are the AT bus,
NuBus, Micro Channel, and EISA bus.

C

C Celsius
CGND chassis ground signal
channel pin or wire lead to which you apply or from which you read the analog

or digital signal. Analog signals can be single-ended or differential. For
digital signals, you group channels to form ports. Ports usually consist

of either four or eight digital channels.
CH<0..31> - negative input channels 0 through 31
CH<0..31>+ positive input channels 0 through 31
CJC cold-junction compensation—a method of compensating for

inaccuracies in thermocouple circuits
CJSENSOR cold-junction sensor

D

DAQ data acquisition—(1) collecting and measuring electrical signals from

sensors, transducers, and test probes or fixtures and inputting them to a

computer for processing; (2) collecting and measuring the same kinds

of electrical signals with A/D and/or DIO boards plugged into a

computer, and possibly generating control signals with D/ A and/or DIO

boards in the same computer
DC direct current

©

VXI-SC-1102/B/C User Manual G-2

National Instruments Corporation

Glossary

DIFF differential configuration
differential input an analog input consisting of two terminals, both of which are isolated

from computer ground, whose difference is measured

drivers/driver software software that controls a specific hardware device such as a DAQ board

F

filtering a type of signal conditioning that allows you to filter unwanted signals

from the signal you are trying to measure

FSR full-scale range

G

G gain—the factor by which a signal is amplified, sometimes expressed in

decibels

H

hex hexadecimal
Hz hertz

I

in. inches
input impedance the measured resistance and capacitance between the input terminals of

a circuit

instrument driver a set of high-level software functions that controls a specific VXI or

RS-232 programmable instrument or a specific plug-in DAQ board.
Instrument drivers are available in several forms, ranging from a
function callable language to a virtual instrument (VI) in LabVIEW.

©

National Instruments Corporation G-3 VXI-SC-1102/B/C User Manual

Glossary

L

logical address An 8-bit number that uniquely identifies each VXIbus device in a

system. It defines the A16 register addresses of a device, and indicates

Commander and Servant relationships.
LSB least significant bit

M

mainframe The chassis of a VXIbus system that mechanically contains VXI

modules inserted into the backplane, ensuring that connectors fit

properly and that adjacent modules do not contact each other. It also

provides cooling airflow, and ensures that modules do not disengage

from the backplane due to vibration or shock.
MB megabytes of memory
MIO multifunction I/O
MSB most significant bit
mux multiplexer—a switching device with multiple inputs that sequentially

connects each of its inputs to its output, typically at high speeds, in

order to measure several signals with a single analog input channel

N

NC not connected (signal)
noise an undesirable electrical signal—Noise comes from external sources

such as the AC power line, motors, generators, transformers,

fluorescent lights, soldering irons, CRT displays, computers, electrical

storms, welders, radio transmitters, and internal sources such as

semiconductors, resistors, and capacitors. Noise corrupts signals you

are trying to send or receive.

©

VXI-SC-1102/B/C User Manual G-4

National Instruments Corporation

Glossary

R

RMA Return Material Authorization
rms root mean square

S

SCMP signal conditioning minipod
signal conditioning the manipulation of signals to prepare them for digitizing
slot A position where a module can be inserted into a VXIbus backplane.

Each slot provides the 96-pin J connectors to interface with the board
P connectors. A slot can have one, two, or three connectors.

S/s samples per second

T

thermocouple a temperature sensor created by joining two dissimilar metals. The

junction produces a small voltage as a function of the temperature.

transducer excitation a type of signal conditioning that uses external voltages and currents

to excite the circuitry of a signal conditioning system into measuring
physical phenomena

V

Vvolts
VAC volts alternating current
V

em

VDC volts, direct current
V

diff

©

National Instruments Corporation G-5 VXI-SC-1102/B/C User Manual

common-mode voltage

differential voltage

Glossary

VI virtual instrument—(1) a combination of hardware and/or software

elements, typically used with a PC, that has the functionality of a classic

stand-alone instrument (2) a LabVIEW software module (VI), which

consists of a front panel user interface and a block diagram program
V

IH

V

IL

V

in

volts, input high

volts, input low

volts in
VISA a new driver software architecture developed by National Instruments

to unify instrumentation softwareGPIB, DAQ, and VXI. It has been

accepted as a standard for VXI by the VXIplug&play Systems Alliance.
V

OH

V

OL

volts, output high

volts, output low
VXIbus VMEbus eXtensions for Instrumentation
VXIplug&play A group of VXI developers dedicated to making VXI devices as easy to

Systems Alliance use as possible, primarily by simplifying software development

W

waveform a time-varying physical phenomenon, often measured in voltage

VXI-SC-1102/B/C User Manual G-6

©

National Instruments Corporation

Index

Numbers

+5 V signal (table), 3-3

A

address handler, 4-2
analog circuitry, 4-3 to 4-4

analog input channels, 4-3
analog output, 4-4

analog input specifications, A-1 to A-4

amplifier characteristics, A-2
dynamic characteristics, A-2 to A-3
input characteristics, A-1
transfer characteristics, A-1 to A-2

analog output, 4-4

B

bulletin board support, C-1

C

calibration, 5-1 to 5-4

equipment requirements, 5-1 to 5-2
gain and offset calibration, 5-2 to 5-4
overview, 5-1

sample program, B-1 to B-4
CGND signal (table), 3-3
CH31- through CH0- signals (table), 3-3
CH31+ through CH0+ signals (table), 3-3

channel input signal connections, 3-3 to 3-4

common-mode input signal range,

3-3 to 3-4
differential input signal range, 3-3
exceeding input levels and ranges

(warning), 3-4
signal terminals, 3-3

Channel Register, 4-2
CJSENSOR signal

cold-junction sensor connection, 3-6
description (table), 3-3
exceeding overvoltage protection

(warning), 3-6

cold-junction sensor connection, 3-6
common-mode input signal range, 3-3 to 3-4
ComponentWorks application software, 1-4
Configuration Register, 4-2
current-loop receivers, installing, 2-3
customer communication, xii, C-1 to C-2

D

differential input signal range, 3-3
digital control circuitry, 4-2 to 4-3
documentation

conventions used in manual, x to xi
National Instruments documentation,

xi to xii
organization of manual, ix to x
related documentation, xii

©

National Instruments Corporation I-1 VXI-SC-1102/B/C User Manual

Index

E

e-mail support, C-2
EEPROM Register, 4-2
electronic support services, customer

communication
environment specifications, A-4
equipment, optional, 1-6

F

FaxBack support, C-2
filler panel, 1-2
filter specifications, A-3
floating signal connection

referenced to chassis ground (figure), 3-6
front connector pin assignments (figure), 3-2
FTP support, C-1

G

gain and offset calibration, 5-2 to 5-4
Gain Register, 4-2
ground-referencing signals, 3-4

floating signal connection

referenced to chassis ground
(figure), 3-6

ground-referenced signal connection

(figure), 3-5

H

hardware installation. See installation.

I

input damage level, exceeding (warning), 3-4
installation, 2-1 to 2-4

current-loop receivers, 2-3
hardware installation, 2-4

parts locator diagram, 2-2
unpacking the VXI-SC-1102/B/C, 1-7

L

LabVIEW application software, 1-4
LabWindows/CVI application software, 1-4

M

manual. See documentation.
Module ID Register, 4-2

N

NI-DAQ driver software, 1-5

P

parts locator diagram, 2-2
physical specifications, A-3
pins

front connector pin assignments

(figure), 3-2

front connector signal descriptions

(table), 3-3

power requirements, A-4

R

requirements for getting started, 1-3
resistors

bent and trimmed resistor (figure), 2-3
disconnecting signals before installing

(warning), 2-3

installing current-loop receivers, 2-3

VXI-SC-1102/B/C User Manual I-2

©

National Instruments Corporation

Index

S

scan interval, minimum, 4-3

settling time (note), 4-3

signal connections, 3-1 to 3-6

channel input signal connections,

3-3to3-4
cold-junction sensor connection, 3-6
front connector pin assignments

(figure), 3-2
ground-referencing signals, 3-4

floating signal connection

referenced to chassis ground
(figure), 3-6

ground-referenced signal connection

(figure), 3-5
signal descriptions (table), 3-3
static electricity damage (caution), 3-1

signal terminals for input channels, 3-3
software programming choices, 1-4 to 1-6

National Instruments application

software, 1-4 to 1-6
NI-DAQ driver software, 1-5
VXIplug&play instrument driver, 1-6

specifications, A-1 to A-4

amplifier characteristics, A-2
dynamic characteristics, A-2 to A-3
environment, A-4
filters, A-3
input characteristics, A-1
physical, A-3
power requirements, A-4
stability, A-3
transfer characteristics, A-1 to A-2

stability specifications, A-3
Status Register, 4-2

T

technical support, customer communication
telephone and fax support, C-2
temperature sensor, 4-3
theory of operation, 4-1 to 4-4

analog circuitry, 4-3 to 4-4

analog input channels, 4-3

analog output, 4-4
block diagram of VXI-SC-1102, 4-1
digital control circuitry, 4-2 to 4-3
functional overview, 4-1 to 4-2
VXIbus interface, 4-2

U

unpacking the VXI-SC-1102, 1-7

V

VirtualBench application software, 1-4
VXI-SC-1000 carrier module, 1-2
VXI-SC-1102/B/C. See also theory

of operation.

features, 1-2 to 1-3
optional equipment, 1-6
parts locator diagram, 2-2
requirements for getting started, 1-3
software programming choices, 1-4 to 1-6

National Instruments application

software, 1-4
NI-DAQ driver software, 1-5
VXIplug&play instrument

driver, 1-6

unpacking, 1-7
VXI signal conditioning system

(figure), 1-1
VXI signal conditioning system (figure), 1-1
VXIbus interface, 4-2
VXIplug&play instrument driver, 1-6

©

National Instruments Corporation I-3 VXI-SC-1102/B/C User Manual