National Instruments SCXI-1121 user manual

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

Contents

Main Page Important Information Warranty Copyright Trademarks WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS Contents About This Manual Chapter 1 Introduction Chapter 2 Configuration and Installation Chapter 3 Theory of Operation Chapter 4 Register Descriptions Chapter 5 Programming Page Figures Tables About This Manual Conventions Related Documentation Introduction What Your Kit Should Contain Optional Software Page Optional Equipment Equipment Part Number Custom Cables Unpacking Configuration and Installation Module Configuration Page Digital Signal Connections Jumper W44 Jumper W38 Jumper W32 Using Jumpers W32 and W38 Page Analog Configuration Grounding, Shielding, and Reference Mode Selection Jumper W33 Page Input Channel Jumpers Gain Jumpers Filter Jumpers Excitation Jumpers Current and Voltage Excitation Jumpers Excitation Level Table 2-6. Voltage and Current Mode Excitation Jumper Setup Excitation Channel Jumpers Voltage Mode (Factory Setting) Current Mode 0W14 and W15 1W22 and W23 2W34 and W35 3W46 and W47 Page Using the Internal Half-Bridge Completion Chapter 2 Configuration and Installation National Instruments Corporation 2-13 SCXI-1121 User Manual 2W27 and W28 3W39 and W40 Table 2-9. Completion Network Jumpers (Continued) Channel Jumpers Enable Completion Disable Network (Factory Setting) Hardware Installation Signal Connections Front Connector Figure 2-3. SCXI-1121 Front Connector Pin Assignment Front Connector Signal Descriptions Page Analog Input Channels Page Excitation Channels Temperature Sensor Connection Connector-and-Shell Assembly Page SCXI-1320, SCXI-1328, and SCXI-1321 TerminalBlocks SCXI-1320 and SCXI-1328 Terminal Blocks SCXI-1321 Offset-Null and Shunt-Calibration Terminal Block Page Page Page Page Terminal Block Temperature Sensor Terminal Block Jumper Configuration Page Terminal Block Signal Connection Page Page Terminal Block Installation Rear Signal Connector Note If you are using the SCXI-1121 with a National Instruments data acquisition board Figure 2-14. SCXI-1121 Rear Signal Connector Pin Assignment Rear Signal Connector Signal Descriptions Analog Output Signal Connections Digital I/O Signal Connections Page Timing Requirements and Communication Protocol Timing Signal Communication Signals Page Page Page Page National Instruments Corporation 3-1 SCXI-1121 User Manual Theory of Operation Figure 3-1. SCXI-1121 Block Diagram Functional Overview The block diagram in Figure 3-1 illustrates the key functional components of the SCXI-1121. Page Chapter 3 Theory of Operation National Instruments Corporation 3-3 SCXI-1121 User Manual SCXIbus Connector Figure 3 -2 shows the pin assignments for the SCXIbus connector. Figure 3-2. SCXIbus Connector Pin Assignment SCXIbus Connector Signal Descriptions Page Digital Interface Digital Control Circuitry Analog and Timing Circuitry Analog Input Channels Figure 3-5. Analog Input Block Diagram Page Excitation Output Channels Calibration Calibration Equipment Requirements Offset Null Adjust Excitation Adjust Page Analog Output Circuitry Page Scanning Modes Single-Module Parallel Scanning Multiplexed Scanning Single-Module Multiplexed Scanning Single-Module Multiplexed Scanning (Direct) Single-Module Multiplexed Scanning (Indirect) Chapter 3 Theory of Operation National Instruments Corporation 3-19 SCXI-1121 User Manual Multiple-Module Multiplexed Scanning Figure 3-10. Multiple-Module Multiplexed Scanning Multiple-Chassis Scanning Register Descriptions Register Description Register Description Format SCXI-1121 Registers Module ID Register Configuration Register Page Slot 0 Register Descriptions Slot-Select Register Hardscan Control Register (HSCR) Page FIFO Register Programming Programming Considerations Notation Register Writes Register Selection and Write Procedure Initialization Single-Channel Measurements Direct Measurements Parallel Output Multiplexed Output Indirect Measurements Measurements from Other Modules Measurements from the SCXI-1121 via Another Module Scanning Measurements 1. Data Acquisition Board Setup Programming Page Counter 1 and SCANDIV 2. Module Programming Single-Module Parallel Scanning Single-Module Multiplexed Scanning (Direct) Single-Module Multiplexed Scanning (Indirect) Multiple-Module Multiplexed Scanning Multiple-Chassis Scanning 3. Programming the Slot 0 Hardscan Circuitry 4. Acquisition Enable, Triggering, and Servicing Scanning Examples Example 1 Example 2 Example 3 Page A Specifications Analog Input Page RTD Mode Strain Gauge Mode Cold-Junction Sensor Physical Environment Safety B Rear Signal Connector Figure B-1. SCXI-1121 Rear Signal Connector Pin Assignment Rear Signal Connector Signal Descriptions Page Appendix C SCXIbus Connector SCXI-1121 User Manual C-2 www.natinst.com FigureC -1 shows the pin assignments for the SCXI-1121 SCXIbus Figure C-1. SCXIbus Connector Pin Assignment SCXIbus Connector Signal Descriptions Page Page Appendix D SCXI-1121 Front Connector SCXI-1121 User Manual D-2 www.natinst.com FigureD -1 shows the pin assignments for the SCXI-1121 front connector. Figure D-1. SCXI-1121 Front Connector Pin Assignment Front Connector Signal Descriptions Page E SCXI-1121 Cabling SCXI-1340 Cable Assembly Page SCXI-1340 Installation SCXI-1341 Lab-NB, Lab-PC, or Lab-PC+ and SCXI-1344 Lab-LC Cable Assembly Page SCXI-1341 and SCXI-1344 Installation SCXI-1342 PC-LPM-16 Cable Assembly Page SCXI-1342 Installation SCXI-1180 Feedthrough Panel SCXI-1180 Installation SCXI-1302 50-Pin Terminal Block SCXI-1302 Wiring Procedure SCXI-1302 Installation SCXI-1351 One-Slot Cable Extender SCXI-1351 Installation SCXI-1350 Multichassis Adapter SCXI-1350 Installation SCXI-1343 Rear Screw Terminal Adapter SCXI-1343 Installation Page Page F Page Page G Technical Support Resources NI Web Support Online Problem-Solving and Diagnostic Resources Software-Related Resources Worldwide Support Glossary Numbers/Symbols A B C D Page Page Page S T U V W Index Numbers A B C D E F G H I J L M N O P R S Page Page T U V W