User ManualTable of ContentsSCXI-1141/1142/1143 User Manual1Support2Worldwide Technical Support and Product Information2National Instruments Corporate Headquarters2Worldwide Offices2Important Information3Warranty3Copyright3Trademarks3Patents3WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS3Conventions4Contents5Chapter 1 About the SCXI-1141/1142/11439What You Need to Get Started10National Instruments Documentation11Installing Application Software, NI-DAQmx, and the DAQ Device12Installing the SCXI-1141/1142/1143 into an SCXI Chassis or a PXI/SCXI Combination Chassis12Installing the Terminal Block12Table 1-1. Accessories Available for the SCXI-1141/1142/114312Verifying the SCXI-1141/1142/1143 Installation in Software13Installing SCXI Chassis and Modules in Software13Troubleshooting the Self-Test Verification13Troubleshooting in NI-DAQmx13Chapter 2 Connecting Signals15Front Connector15Table 2-1. Front Signal Pin Assignments16Front Connector Signal Descriptions17Analog Input Channels17Figure 2-1. Ground-Referenced Signal Connection18Figure 2-2. Floating Signal Connection19Figure 2-3. Ground-Referenced AC-Coupled Signal Connection19Figure 2-4. Ground Offset AC-Coupled Signal Connection20Figure 2-5. Floating AC-Coupled Signal Connection20Digital Input and Output20Rear Signal Connector21Table 2-2. Rear Signal Pin Assignments22Table 2-3. SCXI-1141/1142/1143 Rear Communication Signals23Analog Output Signal Connections25Digital I/O Signal Connections25Table 2-4. SCXIbus to SCXI-1141/1142/1143 Module Rear Signal Connector to DAQ Device Pin Equivalencies26Chapter 3 Configuring and Testing27SCXI-1141/1142/1143 Software-Configurable Settings27Common Software-Configurable Settings27Gain/Input Range27Input Selection28Auto-Zero28Configurable Settings in MAX28NI-DAQmx29Creating a Global Channel or Task29Verifying the Signal30Verifying the Signal in NI-DAQmx Using a Task or Global Channel30Chapter 4 Theory of Operation32Power-Up State32Figure 4-1. SCXI-1141/1142/1143 Module Block Diagram33Digital Control Circuitry34Input Amplifiers34Correcting Gain and Offset Errors35Lowpass Filters36Filter Theory36Figure 4-2. Ideal and Real Lowpass Filter Transfer Function Characteristics36Figure 4-3. Real and Ideal Filter Responses to a Step Input Signal37Performance of the SCXI-1141/1142/1143 Module Filters37Magnitude Response37Figure 4-4. Typical Magnitude Response of the SCXI-1141/1142/1143 Module Filters38Figure 4-5. Typical Passband Responses of the SCXI-1141/1142/1143 Module39Phase Response39Figure 4-6. Phase Response Characteristics of the SCXI-1141/1142/1143 Module Filters40Figure 4-7. Phase Error of the SCXI-1141/1142/1143 Module41Figure 4-8. Unit Step Response of the SCXI-1141/1142/1143 Module42Setting the Cutoff Frequency42Using the SCXI-1141/1142/1143 Module as an Antialiasing Filter43Figure 4-9. Aliasing of an Input Signal with a Frequency 0.8 Times the Sample Rate43Using the External Clock Input45Table 4-1. Cutoff Frequency Ranges for the SCXI-1141/1142/1143 Module Prefilters and Postfilters46DC-Correction Circuitry and Overload Recovery46Filter Bypass Mode47Rear Connector Analog Outputs47Multiplexed Mode (Recommended)47Parallel Mode48Chapter 5 Using the SCXI-1141/1142/1143 Module49Developing Your Application in NI-DAQmx49Typical Program Flowchart49Figure 5-1. Typical Program Flowchart for Voltage Measurement Channels50General Discussion of Typical Flowchart51Creating a Task Using DAQ Assistant or Programmatically51Adjusting Timing and Triggering51Configuring Channel Properties52Table 5-1. NI-DAQmx Voltage Measurement Properties52Table 5-2. NI-DAQmx Thermocouple Measurement Properties53Table 5-3. NI-DAQmx RTD Measurement Properties54Table 5-4. NI-DAQmx Thermistor Measurement Properties54Table 5-5. NI-DAQmx Current Measurement Properties54Acquiring, Analyzing, and Presenting55Completing the Application55Developing an Application Using LabVIEW55Table 5-6. Programming a Task in LabVIEW56Using a NI-DAQmx Channel Property Node in LabVIEW57Specifying Channel Strings in NI-DAQmx58Text Based ADEs58Programmable NI-DAQmx Properties60Calibration61External Calibration61Appendix A Specifications62Table A-1. Settling Time with Respect to Cutoff Frequency64Figure A-1. SCXI-1141/1142/1143 Dimensions66Appendix B Removing the SCXI-1141/1142/1143 Module69Figure B-1. Removing the SCXI-1141/1142/1143 Module70Appendix C Common Questions71Table C-1. Digital SIgnals on the SCXI-1141/1142/114372Glossary75Symbols75A-D76E-I77L-P78R-S79T-W80Index81A-C81D-F82G-M83N-R84S85T-W86Size: 1.19 MBPages: 86Language: EnglishOpen manual
User ManualTable of ContentsSCXI-1141/1142/1143 User Manual1Support2Worldwide Technical Support and Product Information2National Instruments Corporate Headquarters2Worldwide Offices2Important Information3Warranty3Copyright3Trademarks3Patents3WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS3Conventions4Contents5Chapter 1 About the SCXI-1141/1142/11439What You Need to Get Started10National Instruments Documentation11Installing Application Software, NI-DAQmx, and the DAQ Device12Installing the SCXI-1141/1142/1143 into an SCXI Chassis or a PXI/SCXI Combination Chassis12Installing the Terminal Block12Table 1-1. Accessories Available for the SCXI-1141/1142/114312Verifying the SCXI-1141/1142/1143 Installation in Software13Installing SCXI Chassis and Modules in Software13Troubleshooting the Self-Test Verification13Troubleshooting in NI-DAQmx13Chapter 2 Connecting Signals15Front Connector15Table 2-1. Front Signal Pin Assignments16Front Connector Signal Descriptions17Analog Input Channels17Figure 2-1. Ground-Referenced Signal Connection18Figure 2-2. Floating Signal Connection19Figure 2-3. Ground-Referenced AC-Coupled Signal Connection19Figure 2-4. Ground Offset AC-Coupled Signal Connection20Figure 2-5. Floating AC-Coupled Signal Connection20Digital Input and Output20Rear Signal Connector21Table 2-2. Rear Signal Pin Assignments22Table 2-3. SCXI-1141/1142/1143 Rear Communication Signals23Analog Output Signal Connections25Digital I/O Signal Connections25Table 2-4. SCXIbus to SCXI-1141/1142/1143 Module Rear Signal Connector to DAQ Device Pin Equivalencies26Chapter 3 Configuring and Testing27SCXI-1141/1142/1143 Software-Configurable Settings27Common Software-Configurable Settings27Gain/Input Range27Input Selection28Auto-Zero28Configurable Settings in MAX28NI-DAQmx29Creating a Global Channel or Task29Verifying the Signal30Verifying the Signal in NI-DAQmx Using a Task or Global Channel30Chapter 4 Theory of Operation32Power-Up State32Figure 4-1. SCXI-1141/1142/1143 Module Block Diagram33Digital Control Circuitry34Input Amplifiers34Correcting Gain and Offset Errors35Lowpass Filters36Filter Theory36Figure 4-2. Ideal and Real Lowpass Filter Transfer Function Characteristics36Figure 4-3. Real and Ideal Filter Responses to a Step Input Signal37Performance of the SCXI-1141/1142/1143 Module Filters37Magnitude Response37Figure 4-4. Typical Magnitude Response of the SCXI-1141/1142/1143 Module Filters38Figure 4-5. Typical Passband Responses of the SCXI-1141/1142/1143 Module39Phase Response39Figure 4-6. Phase Response Characteristics of the SCXI-1141/1142/1143 Module Filters40Figure 4-7. Phase Error of the SCXI-1141/1142/1143 Module41Figure 4-8. Unit Step Response of the SCXI-1141/1142/1143 Module42Setting the Cutoff Frequency42Using the SCXI-1141/1142/1143 Module as an Antialiasing Filter43Figure 4-9. Aliasing of an Input Signal with a Frequency 0.8 Times the Sample Rate43Using the External Clock Input45Table 4-1. Cutoff Frequency Ranges for the SCXI-1141/1142/1143 Module Prefilters and Postfilters46DC-Correction Circuitry and Overload Recovery46Filter Bypass Mode47Rear Connector Analog Outputs47Multiplexed Mode (Recommended)47Parallel Mode48Chapter 5 Using the SCXI-1141/1142/1143 Module49Developing Your Application in NI-DAQmx49Typical Program Flowchart49Figure 5-1. Typical Program Flowchart for Voltage Measurement Channels50General Discussion of Typical Flowchart51Creating a Task Using DAQ Assistant or Programmatically51Adjusting Timing and Triggering51Configuring Channel Properties52Table 5-1. NI-DAQmx Voltage Measurement Properties52Table 5-2. NI-DAQmx Thermocouple Measurement Properties53Table 5-3. NI-DAQmx RTD Measurement Properties54Table 5-4. NI-DAQmx Thermistor Measurement Properties54Table 5-5. NI-DAQmx Current Measurement Properties54Acquiring, Analyzing, and Presenting55Completing the Application55Developing an Application Using LabVIEW55Table 5-6. Programming a Task in LabVIEW56Using a NI-DAQmx Channel Property Node in LabVIEW57Specifying Channel Strings in NI-DAQmx58Text Based ADEs58Programmable NI-DAQmx Properties60Calibration61External Calibration61Appendix A Specifications62Table A-1. Settling Time with Respect to Cutoff Frequency64Figure A-1. SCXI-1141/1142/1143 Dimensions66Appendix B Removing the SCXI-1141/1142/1143 Module69Figure B-1. Removing the SCXI-1141/1142/1143 Module70Appendix C Common Questions71Table C-1. Digital SIgnals on the SCXI-1141/1142/114372Glossary75Symbols75A-D76E-I77L-P78R-S79T-W80Index81A-C81D-F82G-M83N-R84S85T-W86Size: 1.19 MBPages: 86Language: EnglishOpen manual