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™
SCXI
SCXI-1121 User Manual
Four-Channel Isolated Universal Transducer Module
for Signal Conditioning
SCXI-1121 User Manual
September 1999 Edition
Part Number 320426C-01
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Worldwide Technical Support and Product Information www.natinst.com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin, Texas 78759-3504 USA Tel: 512 794 0100 Worldwide Offices Australia 03 9879 5166, Austria 0662 45 79 90 0, Belgium 02 757 00 20, Brazil 011 284 5011, Canada (Calgary) 403 274 9391, Canada (Ontario) 905 785 0085, Canada (Québec) 514 694 8521, China 0755 3904939, Denmark 45 76 26 00, Finland 09 725 725 11, France 01 48 14 24 24, Germany 089 741 31 3
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Important Information Warranty The SCXI-1121 is 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. A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the outside of the pack
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Contents About This Manual Conventions ...................................................................................................................xi Related Documentation..................................................................................................xii Chapter 1 Introduction What Your Kit Should Contain .....................................................................................1-2 Optional Software .............................................................
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Contents Chapter 3 Theory of Operation Functional Overview ..................................................................................................... 3-1 SCXIbus Connector ........................................................................................ 3-3 SCXIbus Connector Signal Descriptions........................................................ 3-4 Digital Interface.............................................................................................................
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Contents 2. Module Programming ...................................................................5-10 3. Programming the Slot 0 Hardscan Circuitry.................................5-13 4. Acquisition Enable, Triggering, and Servicing.............................5-14 Scanning Examples........................................................................................................5-15 Example 1..................................................................................................
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Contents Figures Figure 2-1. SCXI-1121 General Parts Locator Diagram ......................................... 2-2 Figure 2-2. SCXI-1121 Detailed Parts Locator Diagram ........................................ 2-3 Figure 2-3. SCXI-1121 Front Connector Pin Assignment ...................................... 2-18 Figure 2-4. Ground-Referenced Signal Connection with High Common-Mode Voltage .............................................................. 2-21 Figure 2-5. Floating Signal Connection Refe
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Contents Figure E-2. SCXI-1180 Rear Connections...............................................................E-9 Figure E-3. SCXI-1180 Front Panel Installation......................................................E-10 Figure E-4. Cover Removal......................................................................................E-11 Figure F-1. Revision A and B SCXI-1121 Signal Conditioning Module ................F-1 Figure F-2. Revision A and B SCXI-1121 General Parts Locator Diagram...........
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About This Manual This manual describes the electrical and mechanical aspects of the SCXI-1121 and contains information concerning its operation and programming. The SCXI-1121 is a member of the National Instruments Signal Conditioning eXtensions for Instrumentation (SCXI) Series for the National Instruments data acquisition plug-in boards. This board is designed for signal conditioning of strain gauges, RTDs, thermistors, thermocouples, volt and millivolt sources, and 4 to 20 mA sources
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About This Manual monospace Text in this font denotes text or characters that you should enter 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, operations, variables, filenames and extensions, and code excerpts. monospace italic Italic text in this font denotes text that is a placeholder for a word or value that you must
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1 Introduction This chapter describes the SCXI-1121; lists the contents of your SCXI-1121 kit; describes the optional software, optional equipment, and custom cables; and explains how to unpack the SCXI-1121 kit. The SCXI-1121 consists of four isolated input channels and four isolated excitation channels. The SCXI-1121 is a module for signal conditioning of strain gauges, RTDs, thermistors, thermocouples, volt and millivolt sources, 4 to 20 mA current sources, and 0 to 20 mA process-current
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Chapter 1 Introduction What Your Kit Should Contain The contents of the SCXI-1121 kit (part number 776572-21) are listed as follows: Kit Component Part Number SCXI-1121 module 181700-01 SCXI-1121 User Manual 320426-01 If your kit is missing any of the components, contact National Instruments. Optional Software This manual contains complete instructions for directly programming the SCXI-1121. You can order separate software packages for controlling the SCXI-1121 from National Instruments. When
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Chapter 1 Introduction for DOS and Visual Basic, Turbo Pascal, Microsoft C with SDK, and Borland C++ for Windows. NI-DAQ software for DOS/Windows/LabWindows is on high-density 5.25 in. and 3.5 in. diskettes. You can use the SCXI-1121, together with the Lab-LC or NB Series data acquisition boards, with LabVIEW for Macintosh, a software system that features interactive graphics, a state-of-the-art user interface, and a powerful graphical programming language. The LabVIEW Data Acquisition VI
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Chapter 1 Introduction Optional Equipment Equipment Part Number NB6 cable 0.5 m 181305-01 1.0 m 181305-10 SCXI-1320 front terminal block 776573-20 SCXI-1321 offset-null and shunt-calibration terminal block 776573-21 SCXI-1328 high-accuracy isothermal terminal block 776573-28 SCXI-1330 32-pin connector-and-shell assembly 776573-30 SCXI-1340 cable assembly 776574-40 SCXI-1341 Lab-NB/Lab-PC/Lab-PC+ cable assembly 776574-41 SCXI-1342 PC-LPM-16 cable assembly 776574-42 SCXI-1343 rear screw terminal a
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Chapter 1 Introduction Refer to the Signal Connections section in Chapter 2, Configuration and Installation, and to Appendix E, SCXI-1121 Cabling, for additional information on cabling, connectors, and adapters. Custom Cables The SCXI-1121 rear signal connector is a 50-pin male ribbon-cable header. The manufacturer part number used by National Instruments for this header is as follows: • AMP Inc. (part number 1-103310-0) The mating connector for the SCXI-1121 rear signal connector is a 50-p
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Chapter 1 Introduction Unpacking Your SCXI-1121 module is shipped in an antistatic package to prevent electrostatic damage to the module. Several components on the module can be damaged by electrostatic discharge. To avoid such damage in handling the module, take the following precautions. • 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 oth
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2 Configuration and Installation This chapter describes the SCXI-1121 jumper configurations, installation of the SCXI-1121 into the SCXI chassis, signal connections to the SCXI-1121, and cable wiring. Module Configuration The SCXI-1121 contains 49 jumpers that are shown in the parts locator diagrams in Figures 2-1 and 2-2. Figure 2-1. SCXI-1121 General Parts Locator Diagram © National Instruments Corporation 2-1 SCXI-1121 User Manual
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Chapter 2 Configuration and Installation Figure 2-2. SCXI-1121 Detailed Parts Locator Diagram The jumpers are used as follows: • Fixed jumpers – On Revision A and B modules, jumper W32 is unused and should not be connected. – Jumper W45 is reserved and should not be reconfigured. – On Revision A and B modules, jumper W44 carries the SLOT0SEL* signal from the rear signal connector, after buffering, to the SCXIbus INTR* line and should be left in the factory-set position (position 1). On Revi
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Chapter 2 Configuration and Installation – Jumpers W3, W19, W29, and W41 configure the first-stage gain of input channels 0 through 3, respectively. – Jumpers W4, W20, W30, and W42 configure the second-stage gain of input channels 0 through 3, respectively. – Jumpers W5, W21, W31, and W43 configure the first-stage filtering of input channels 0 through 3, respectively. – Jumpers W6 and W7, W8 and W9, W10 and W11, and W12 and W13 configure the second-stage filtering of input channels 0 throug
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Chapter 2 Configuration and Installation On Revision C or later modules, jumper W44 does not exist. SLOT0SEL* is always buffered to the INTR* line. Jumper W38 Position 1 connects, after buffering, the SCXIbus MISO line to the SERDATOUT pin of the rear signal connector. In this setting, along with the proper setting of W32, the data acquisition board can read the Module ID Register of the SCXI-1121. See the Timing Requirements and Communication Protocol section later in this chapter, and Cha
