Network Card User Manual
Table Of Contents
- SCXI-1121 User Manual
- Support
- Important Information
- Contents
- About This Manual
- Chapter 1 Introduction
- Chapter 2 Configuration and Installation
- Chapter 3 Theory of Operation
- Chapter 4 Register Descriptions
- Chapter 5 Programming
- Appendix A Specifications
- Appendix B Rear Signal Connector
- Appendix C SCXIbus Connector
- Appendix D SCXI-1121 Front Connector
- Appendix E SCXI-1121 Cabling
- Appendix F Revision A and B Photo and Parts Locator Diagrams
- Appendix G Technical Support Resources
- Glossary
- Index
- Figures
- Figure 2-1. SCXI-1121 General Parts Locator Diagram
- Figure 2-2. SCXI-1121 Detailed Parts Locator Diagram
- Figure 2-3. SCXI-1121 Front Connector Pin Assignment
- Figure 2-4. Ground-Referenced Signal Connection with High Common-Mode Voltage
- Figure 2-5. Floating Signal Connection Referenced to Chassis Ground for Better Signal-to-Noise Ratio
- Figure 2-6. Floating AC-Coupled Signal Connection
- Figure 2-7. AC-Coupled Signal Connection with High Common-Mode Voltage
- Figure 2-8. Assembling and Mounting the SCXI-1330 Connector-and-Shell Assembly
- Figure 2-9. Nulling Circuit
- Figure 2-10. Shunt Circuit
- Figure 2-11. SCXI-1320 Parts Locator Diagram
- Figure 2-12. SCXI-1328 Parts Locator Diagram
- Figure 2-13. SCXI-1321 Parts Locator Diagram
- Figure 2-14. SCXI-1121 Rear Signal Connector Pin Assignment
- Figure 2-15. SCANCLK Timing Requirements
- Figure 2-16. Slot-Select Timing Diagram
- Figure 2-17. Serial Data Timing Diagram
- Figure 2-18. Configuration Register Write Timing Diagram
- Figure 2-19. SCXI-1121 Module ID Register Timing Diagram
- Figure 3-1. SCXI-1121 Block Diagram
- Figure 3-2. SCXIbus Connector Pin Assignment
- Figure 3-3. Digital Interface Circuitry Block Diagram
- Figure 3-4. SCXI-1121 Digital Control
- Figure 3-5. Analog Input Block Diagram
- Figure 3-6. Analog Output Circuitry
- Figure 3-7. Single-Module Parallel Scanning
- Figure 3-8. Single-Module Multiplexed Scanning (Direct)
- Figure 3-9. Single-Module Multiplexed Scanning (Indirect)
- Figure 3-10. Multiple-Module Multiplexed Scanning
- Figure 3-11. Multiple-Chassis Scanning
- Figure B-1. SCXI-1121 Rear Signal Connector Pin Assignment
- Figure C-1. SCXIbus Connector Pin Assignment
- Figure D-1. SCXI-1121 Front Connector Pin Assignment
- Figure E-1. SCXI-1340 Installation
- Figure E-2. SCXI-1180 Rear Connections
- Figure E-3. SCXI-1180 Front Panel Installation
- Figure E-4. Cover Removal
- Figure F-1. Revision A and B SCXI-1121 Signal Conditioning Module
- Figure F-2. Revision A and B SCXI-1121 General Parts Locator Diagram
- Figure F-3. Revision A and B SCXI-1121 Detailed Parts Locator Diagram
- Tables
- Table 2-1. Digital Signal Connections, Jumper Settings
- Table 2-2. Jumper W33 Settings
- Table 2-3. Gain Jumper Allocation
- Table 2-4. Gain Jumper Positions
- Table 2-5. Filter Jumper Allocation
- Table 2-6. Voltage and Current Mode Excitation Jumper Setup
- Table 2-7. Maximum Load per Excitation Channel
- Table 2-8. Excitation Level Jumper Selection
- Table 2-9. Completion Network Jumpers
- Table 2-10. Trimmer Potentiometer and Corresponding Channel
- Table 2-11. Nulling Resistors and Corresponding Channel
- Table 2-12. Jumper Settings of the Nulling Circuits
- Table 2-13. Jumper Settings on the SCXI-1320 Terminal Block
- Table 2-14. Jumper Settings on the SCXI-1328 Terminal Block
- Table 2-15. Jumper Settings on the SCXI-1321 Terminal Block
- Table 2-16. SCXIbus to SCXI-1121 Rear Signal Connector to Data Acquisition Board Pin Equivalences
- Table 3-1. SCXIbus Equivalents for the Rear Signal Connector
- Table 3-2. Calibration Potentiometer Reference Designators
- Table 5-1. SCXI-1121 Rear Signal Connector Pin Equivalences
- Table E-1. SCXI-1121 and MIO-16 Pinout Equivalences
- Table E-2. SCXI-1341 and SCXI-1344 Pin Translations
- Table E-3. SCXI-1342 Pin Translations
- Table E-4. SCXI-1343 Pin Connections
Chapter 2 Configuration and Installation
© National Instruments Corporation 2-27 SCXI-1121 User Manual
Assuming a strain-gauge range with a gauge factor of GF = 2 and a
quarter-bridge configuration, this range corresponds to ±1,498 µε as given
by the strain formula for a quarter-bridge strain-gauge configuration:
where
Figure 2-9. Nulling Circuit
Using the SCXI-1321 with RTDs and Thermistors
When using this terminal block with RTDs or thermistor-type transducers
and with the SCXI-1121 excitation set in the Current mode, you must
disable the nulling circuit of the channel of interest. You can do this in two
steps:
1. Place the enable/disable jumper in position D (disable) as shown in
Table 2-12.
2. Remove the nulling resistor from its sockets.
ε
–4V
r
GF 12V
r
+()
-------------------------------=
V
r
strained voltage static unstrained voltage–
V
exc
--------------------------------------------------------------------------------------------------------=
Trimmer
Potentiometer
EX+
R
d
R
g
R
null
CH+
EX–
SCXI-1321
R
R
CH–