National Instruments NI PXI-7831R Input Modes, Input Range

Chapter 2 Hardware Overview ofthe NI PXI-7831R

© National Instruments Corporation 2-3 NI PXI-7831R User Manual

Input Modes

The NIPXI-783 1R input mode is software configurable. The input

channels support three input modes—differential (DIFF) input, referenced

single-ended (RSE) input, and nonreferenced single-ended (NRSE) input.

The selected input mode applies to all the input channels. Table2-2

describes the three input modes.

Input Range

The NIPXI-783 1R AI range is fixed at ±10V.

Midscale 0.000000 0000

Negative full-scale range +1LSB –9.999695 8001

Negative full-scale range –10.000000 8000

Any input voltage —

Table 2-2. Available Input Modes for the NIPXI-7831R

Input Mode Description

DIFF When the NIPX I-7831R is configured in DIFF input mode, each channel uses

two AI lines. The positive input pin connects to the positive terminal of the

onboard instrumentation amplifier, and the negative input pin connects to the

negative input of the instrumentation amplifier.

RSE When the NI PXI-7831R is configured in RSE input mode, each channel uses

only its positive AI pin. This pin connects to the positive terminal of the onboard

instrumentation amplifier. The negative input of the instrumentation amplifier is

internally tied to the AI ground (AIGND).

NRSE When the NIPXI-783 1R is configured in NRSE input mode, each channel uses

only its positive AI pin. This pin connects to the positive terminal of the onboard

instrumentation amplifier. The negative input of the instrumentation amplifier on

each AI channel is internally connected to the AI sense (AISENSE) input pin.

Table 2-1. Ideal Output Code and AI Voltage Mapping (Continued)

Input Description AI Voltage

Output Code (Hex)

(Two’sComplement)

Output Code

32,768

----------------------------------10.0 V×

Contents

Main Page Important Information Warranty Copyright Trademarks Patents Compliance FCC/Canada Radio Frequency Interference Compliance Determining FCC Class FCC/DOC Warnings Class A Contents About This Manual Chapter 1 Introduction Chapter 2 Hardware Overview of the NI PXI-7831R Page About This Manual Conventions Reconfigurable I/O Documentation Related Documentation Introduction About the Reconfigurable I/O Devices Using PXI with CompactPCI What You Need to Get Started Getting Started with Windows 2000/XP Getting Started with the RT Module 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 Page Reconfigurable I/O Applications Software Development FPGA Module RT Module Cables and Optional Equipment Custom Cabling Unpacking Safety Information Page Page National Instruments Corporation 2-1 NI PXI-7831R User Manual Hardware Overview of the NI PXI-7831R PXI/CompactPCI Bus Figure 2-1. NIPXI-7831R Block Diagram + Calibration DACs Analog Input Input Modes Input Range Connecting Analog Input Signals Types of Signal Sources Floating Signal Sources Ground-Referenced Signal Sources Input Modes Figure 2-4. 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 PXI Trigger Bus PXI Local Bus Switch Settings Power Connections Field Wiring Considerations Page Calibration Loading Calibration Constants Internal Calibration External Calibration A Specifications Analog Input Input Characteristics Accuracy Information DC Transfer Characteristics Dynamic Characteristics 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 Environmental Safety Electromagnetic Compatibility CE Compliance B Connecting I/O Signals Page Appendix B Connecting I/O Signals National Instruments Corporation B-3 NI PXI-7831R User Manual Figure B-2. NIPXI-7831R 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 5B and SSR Signal Conditioning Table B-2. NIPXI-7831R I/O Signal Summary Page 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 Appendix C Using the SCB-68 ShieldedConnector Block NI PXI-7831R User Manual C-2 ni.com Quick Reference Label S5 S4 S1 Figure C-2. SCB-68 Quick Reference Label for the NIPXI-7831R 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