National Instruments NI 7831R - page 37

Chapter 2 Hardware Overview ofthe NI 7831R

NI 7831R User Manual 2-18 ni.com

Figure2-11 shows signal connections for three typical DIO applications.

Figure 2-11. Example Digital I/O Connections

Figure2-11 shows DIO<0..3> configured for digital input and DIO<4..7>

configured for digital output. Digital input applications include receiving

TTL, LVTTL, CMOS, or LVCMOS signals and sensing external device

states, such as the state of the switch shown in the figure. Digital output

applications include sending TTL or LVCMOS signals and driving external

devices, such as the LED shown in Figure2-11.

The NI78 31R SH68-C68-S shielded cable contains 34 twisted pairs of

conductors. To maximize the digital I/O available on the NI7831R, some

of the DIO lines are twisted with power or ground and some DIO lines are

twisted with other DIO lines. To obtain maximum signal integrity, place

edge-sensitive or high-frequency digital signals on the DIO lines that are

*3.3 V CMOS

†Use a pull-up resistor when driving 5 V CMOS devices.

LED

TTL, LVTTL, CMOS, or LVCMOS Signal

+5 V

Switch

I/O Connector

DGND

NI 7831R

DIO<0..3>

DIO<4..7>

+5 V

5 V CMOS†

TTL or

LVCMOS*

Compatible

Devices

DGND

Contents

Main Page Important Information Warranty Copyright Trademarks Patents Compliance Compliance with FCC/Canada Radio Frequency Interference Regulations Determining FCC Class FCC/DOC Warnings Class A Contents About This Manual Chapter 1 Introduction Chapter 2 Hardware Overview of the NI 7831R Page About This Manual Conventions Reconfigurable I/O Documentation Related Documentation Introduction About the NI 7831R Using PXI with CompactPCI Overview of Reconfigurable I/O Reconfigurable I/O Concept Flexible Functionality User-Defined I/O Resources Device-Embedded Logic and Processing Reconfigurable I/O Architecture Reconfigurable I/O Applications Software Development LabVIEW FPGA Module LabVIEW Real-Time Module Cables and Optional Equipment Custom Cabling Safety Information Page National Instruments Corporation 2-1 NI 7831R User Manual Hardware Overview of the NI 7831R RTSI/PXI Triggers Connector 0 (MIO) PCI/PXI/CompactPCI Bus Figure 2-1. NI7831R Block Diagram Page Analog Input Input Modes Input Range Connecting Analog Input Signals Page Types of Signal Sources Floating Signal Sources Ground-Referenced Signal Sources Input Modes Figure 2-5. Summary of Analog Input Connections Differential Connection Considerations (DIFF Input Mode) Differential Connections for Ground-Referenced Signal Sources Differential Connections for Nonreferenced or Floating Signal Sources Page Single-Ended Connection Considerations Single-Ended Connections for Floating Signal Sources (RSE Input Mode) Single-Ended Connections for Grounded Signal Sources (NRSE Input Mode) Common-Mode Signal Rejection Considerations Analog Output Connecting Analog Output Signals Digital I/O Connecting Digital I/O Signals Page Page RTSI Trigger Bus PXI Local Bus (for NI PXI-7831R only) Switch Settings Power Connections Field Wiring Considerations Calibration Loading Calibration Constants Internal Calibration External Calibration A Specifications Analog Input Input Characteristics Accuracy Information DC Transfer Characteristics Dynamic Characteristics Settling Time Analog Output Output Characteristics Accuracy Information DC Transfer Characteristics Voltage Output Dynamic Characteristics Digital I/O Reconfigurable FPGA Calibration Bus Interface Power Requirement Physical Maximum Working Voltage Storage Environment Shock and Vibration (for NI PXI-7831R Only) Safety Electromagnetic Compatibility CE Compliance B Connecting I/O Signals Appendix B Connecting I/O Signals NI 7831R User Manual B-2 ni.com Figure B-2. NI7831R I/O Connector Pin Assignments DIO Connector Pin Assignment MIO Connector Pin Assignment Caution Connections that exceed any of the maximum ratings of input or output signals Table B-1. I/O Connector Signal Descriptions Connecting to CompactRIO Extension I/O Chassis Table B-2. NI7831R I/O Signal Summary Connecting to 5B and SSR Signal Conditioning Figure B-3. Connector Pinouts when Using NSC68-262650 Cable AO 07 Connector AI 07 Connector DIO 015 Connector Figure B-4. Connector Pinouts when Using the NSC68-5050 Cable DIO 023 Connector DIO 2439 Connector C Using the SCB-68 Shielded Connector Block D Technical Support and Professional Services Page Glossary Numbers/Symbols A B C D Page I L M N O P R S T V W