National Instruments NI 783xR User Manual

Page 1
Reconfigurable I/O
NI 783x R User Manual
Reconfigurable I/O Devices for PCI/PXI/CompactPCI Bus Computers

NI 783xR User Manual

May 2005 370489C-01
Page 2

Support

ni.com

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For further support information, refer to the Technical Support and Professional Services appendix. To comment on National Instruments documentation, refer to the National Instruments Web site at ni.com/info and enter the info code feedback.
© 2003–2005 National Instruments Corporation. All rights reserved.
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Important Information

Warranty

The NI 7830R/7831R/7833R is warranted against defects in materials and workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period. This warranty includes parts and labor.
The media on which you receive National Instruments software are warranted not to fail to execute programming instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period. National Instruments does not warrant that the operation of the software shall be uninterrupted or error free.
A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work. National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty.
National Instruments believes that the information in this document is accurate. The document has been carefully reviewed for technical accuracy. In the event that technical or typographical errors exist, National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition. The reader should consult National Instruments if errors are suspected. In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it.
E
XCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED, AND SPECIFICALLY DISCLAIMS ANY WAR RANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE . CUSTOMERS RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF
N
ATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER. NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA, PROFITS, USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSS IBILITY THEREOF. This limitation of the liability of National Instruments will apply regardless of the form of action, whether in contract or tort, including
negligence. Any action against National Instruments must be brought within one year after the cause of action accrues. National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control. The warranty provided herein does not cover damages, defects, malfunctions, or service failures caused by owner’s failure to follow the National Instruments installation, operation, or maintenance instructions; owner’s modification of the product; owner’s abuse, misuse, or negligent acts; and power failure or surges, fire, flood, accident, actions of third parties, or other events outside reasonable control.

Copyright

Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical, including photocopying, recording, storing in an information retrieval system, or translating, in whole or in part, without the prior written consent of National Instruments Corporation.

Trademarks

National Instruments, NI, ni.com, and LabVIEW are trademarks of National Instruments Corporation. Refer to the Terms of Use section on
ni.com/legal for more information about National Instruments trademarks.
Members of the National Instruments Alliance Partner Program are business entities independent from National Instruments and have no agency, partnership, or joint-venture relationship with National Instruments.

Patents

For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software, the patents.txt file on your CD, or ni.com/patents.

WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS

(1) NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN.
(2) IN ANY APPLICATION, INCLUDING THE ABOVE, RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS, INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY, COMPUTER HARDWARE MALFUNCTIONS, COMPUTER OPERATING SYSTEM SOFTWARE FITNESS, FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION, INSTALLATION ERRORS, SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS, MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES, TRANSIENT FAILURES OF ELECTRONIC SYSTEMS (HARDWARE AND/OR SOFTWARE), UNANTICIPATED USES OR MISUSES, OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER (ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED “SYSTEM FAILURES”). ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS (INCLUDING THE RISK OF BODILY INJURY AND DEATH) SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE. TO AVOID DAMAGE, INJURY, OR DEATH, THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES, INCLUDING BUT NOT LIMITED TO BACK-UP OR SHUT DOWN MECHANISMS. BECAUSE EACH END-USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS' TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS, THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION, INCLUDING, WITHOUT LIMITATION, THE APPROPRIATE DESIGN, PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION.
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Compliance

Compliance with FCC/Canada Radio Frequency Interference Regulations
Determining FCC Class
The Federal Communications Commission (FCC) has rules to protect wireless communications from interference. The FCC places digital electronics into two classes. These classes are known as Class A (for use in industrial-commercial locations only) or Class B (for use in residential or commercial locations). All National Instruments (NI) products are FCC Class A products.
Depending on where it is operated, this Class A product could be subject to restrictions in the FCC rules. (In Canada, the Department of Communications (DOC), of Industry Canada, regulates wireless interference in much the same way.) Digital electronics emit weak signals during normal operation that can affect radio, television, or other wireless products.
All Class A products display a simple warning statement of one paragraph in length regarding interference and undesired operation. The FCC rules have restrictions regarding the locations where FCC Class A products can be operated.
Consult the FCC Web site at
FCC/DOC Warnings
This equipment generates and uses radio frequency energy and, if not installed and used in strict accordance with the instructions in this manual and the CE marking Declaration of Conformity*, may cause interference to radio and television reception. Classification requirements are the same for the Federal Communications Commission (FCC) and the Canadian Department of Communications (DOC).
Changes or modifications not expressly approved by NI could void the user’s authority to operate the equipment under the FCC Rules.
Class A
Federal Communications Commission
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user is required to correct the interference at their own expense.
www.fcc.gov for more information.
Canadian Department of Communications
This Class A digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations. Cet appareil numérique de la classe A respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada.
Compliance with EU Directives
Users in the European Union (EU) should refer to the Declaration of Conformity (DoC) for information* pertaining to the CE marking. Refer to the Declaration of Conformity (DoC) for this product for any additional regulatory compliance information. To obtain the DoC for this product, visit and click the appropriate link in the Certification column.
* The CE marking Declaration of Conformity contains important supplementary information and instructions for the user or
installer.
ni.com/certification, search by model number or product line,
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Contents

About This Manual
Conventions ...................................................................................................................vii
Reconfigurable I/O Documentation...............................................................................viii
Related Documentation..................................................................................................ix
Chapter 1 Introduction
About the NI 783xR.......................................................................................................1-1
Using PXI with CompactPCI.........................................................................................1-2
Overview of Reconfigurable I/O ...................................................................................1-3
Reconfigurable I/O Concept............................................................................1-3
Reconfigurable I/O Architecture .....................................................................1-4
Reconfigurable I/O Applications.....................................................................1-5
Software Development ..................................................................................................1-5
LabVIEW FPGA Module................................................................................1-5
LabVIEW Real-Time Module .........................................................................1-6
Cables and Optional Equipment ....................................................................................1-7
Custom Cabling .............................................................................................................1-8
Safety Information .........................................................................................................1-9
Flexible Functionality .......................................................................1-3
User-Defined I/O Resources .............................................................1-4
Device-Embedded Logic and Processing .........................................1-4
Chapter 2 Hardware Overview of the NI 783x R
NI 7830R Overview.......................................................................................................2-2
NI 7831R/7833R Overview ...........................................................................................2-2
Analog Input ..................................................................................................................2-2
Input Modes.....................................................................................................2-3
Input Range .....................................................................................................2-4
Connecting Analog Input Signals ..................................................................................2-4
Types of Signal Sources ................................................................................................2-6
Floating Signal Sources...................................................................................2-6
Ground-Referenced Signal Sources ................................................................2-6
© National Instruments Corporation v NI 783xR User Manual
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Contents
Input Modes................................................................................................................... 2-6
Analog Output ............................................................................................................... 2-14
Connecting Analog Output Signals ............................................................................... 2-14
Digital I/O...................................................................................................................... 2-15
Connecting Digital I/O Signals ..................................................................................... 2-15
RTSI Trigger Bus .......................................................................................................... 2-18
PXI Local Bus (for NI PXI-783xR only) ...................................................................... 2-19
Switch Settings .............................................................................................................. 2-20
Power Connections........................................................................................................ 2-23
Field Wiring Considerations..........................................................................................2-24
Chapter 3 Calibration
Loading Calibration Constants ...................................................................................... 3-1
Internal Calibration........................................................................................................ 3-1
External Calibration....................................................................................................... 3-2
Differential Connection Considerations (DIFF Input Mode) ......................... 2-8
Differential Connections for Ground-Referenced Signal Sources ... 2-8 Differential Connections for Nonreferenced or
Floating Signal Sources ................................................................. 2-9
Single-Ended Connection Considerations ...................................................... 2-11
Single-Ended Connections for Floating Signal Sources
(RSE Input Mode).......................................................................... 2-12
Single-Ended Connections for Grounded Signal Sources
(NRSE Input Mode)....................................................................... 2-12
Common-Mode Signal Rejection Considerations........................................... 2-13
Appendix A Specifications
Appendix B Connecting I/O Signals
Appendix C Using the SCB-68 Shielded Connector Block
Appendix D Technical Support and Professional Services
Glossary
NI 783xR User Manual vi ni.com
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About This Manual

This manual describes the electrical and mechanical aspects of the National Instruments 783xR devices and contains information about programming and using the devices.

Conventions

The following conventions appear in this manual:
<> Angle brackets that contain numbers separated by an ellipsis represent a
range of values associated with a bit or signal name—for example, DIO<3..0>.
» The » symbol leads you through nested menu items and dialog box options
to a final action. The sequence File»Page Setup»Options directs you to pull down the File menu, select the Page Setup item, and select Options from the last dialog box.
This icon denotes a note, which alerts you to important information.
This icon denotes a caution, which advises you of precautions to take to avoid injury, data loss, or a system crash. When this symbol is marked on the device, refer to the Safety Information section of Chapter 1,
Introduction, for precautions to take.
bold Bold text denotes items that you must select or click in the software, such
as menu items and dialog box options. Bold text also denotes parameter names and hardware labels.
italic Italic text denotes variables, emphasis, a cross reference, or an introduction
to a key concept. This font also denotes text that is a placeholder for a word or value that you must supply.
monospace Text in this font denotes text or characters that you should enter from the
keyboard, sections of code, programming examples, and syntax examples. This font is also used for the proper names of disk drives, paths, directories, programs, subprograms, subroutines, device names, functions, operations, variables, filenames, and extensions.
NI 783xRNI783xR refers to all PXI and PCI R Series devices with analog and
digital I/O.
© National Instruments Corporation vii NI 783xR User Manual
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About This Manual

Reconfigurable I/O Documentation

The NI 783xR User Manual is one piece of the documentation set for your reconfigurable I/O system and application. Depending on the hardware and software you use for your application, you could have any of several types of documentation. The documentation includes the following documents:
Getting Started with the NI 783xR—This document lists what you need to get started, describes how to unpack and install the hardware and software, and contains information about connecting I/O signals to the NI 783xR.
LabVIEW FPGA Module Release Notes—This document contains information about installing and getting started with the LabVIEW FPGA Module. Select Start»Program Files»National
Instruments»<LabVIEW>»Module Documents»LabVIEW FPGA»Release Notes to view this document.
LabVIEW FPGA Module User Manual—This manual describes how to use the LabVIEW FPGA Module to create virtual instruments (VIs) that run on the NI 783xR. Select Start»Program Files»National
Instruments»<LabVIEW>»Module Documents»FPGA User Interface to view this document.
FPGA Interface User Guide—This manual describes how to control and communicate with FPGA VIs running on R Series devices. Select
Start»Program Files»National Instruments»<LabVIEW>» Module Documents»LabVIEW FPGA»LabVIEW FPGA Module User Manual to view this document.
LabVIEW Help—This help file contains information about using LabVIEW, the LabVIEW FPGA Module, and the LabVIEW Real-Time Module with the NI 783xR. Select Help»VI, Function, & How-To Help in LabVIEW to view the LabVIEW Help.
LabVIEW Real-Time Module User Manual—This manual contains information about how to build deterministic applications using the LabVIEW Real-Time Module.
NI 783xR User Manual viii ni.com
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Related Documentation

The following documents contain information you might find helpful:
NI Developer Zone tutorial, Field Wiring and Noise Considerations for Analog Signals, at
PICMG CompactPCI 2.0 R3.0
PXI Hardware Specification Revision 2.1
PXI Software Specification Revision 2.1
About This Manual
ni.com/zone
© National Instruments Corporation ix NI 783xR User Manual
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Introduction
This chapter describes the NI 783xR, the concept of the Reconfigurable I/O (RIO) device, optional software and equipment for using the NI 783xR, and safety information about the NI 783xR.

About the NI 783x R

The NI 783xR devices are R Series RIO devices with 16-bit analog input (AI) channels, 16-bit analog output (AO) channels, and digital I/O (DIO) lines.
The NI PXI-7830R and NI PCI-7830R have four independent AI channels, four independent AO channels, and 56 DIO lines.
The NI PXI-7831R/7833R and NI PCI-7831R/7833R have eight independent AI channels, eight independent AO channels, and 96 DIO lines.
A user-reconfigurable FPGA (Field-Programmable Gate Array) controls the digital and analog I/O lines on the NI 783xR. The FPGA on the R Series device allows you to define the functionality and timing of the device. You can change the functionality of the FPGA on the R Series device in LabVIEW using the LabVIEW FPGA Module to create and download a custom virtual instrument (VI) to the FPGA. Using the FPGA Module, you can graphically design the timing and functionality of the R Series device. If you only have LabVIEW but not the FPGA Module, you cannot create new FPGA VIs, but you can create VIs that run on Windows or a LabVIEW Real-Time (RT) target to control existing FPGA VIs.
1
Some applications require tasks such as real-time, floating-point processing or datalogging while performing I/O and logic on the R Series device. You can use the LabVIEW Real-Time Module to perform these additional applications while communicating with and controlling the R Series device.
The R Series device contains Flash memory to store a startup VI for automatic loading of the FPGA when the system is powered on.
© National Instruments Corporation 1-1 NI 783xR User Manual
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Chapter 1 Introduction
The NI 783xR uses the Real-Time System Integration (RTSI) bus to easily synchronize several measurement functions to a common trigger or timing event. The NI PCI-783xR accesses the RTSI bus through a RTSI cable connected between devices. The NI PXI-783xR accesses the RTSI bus through the PXI trigger lines implemented on the PXI backplane.
Refer to Appendix A, Specifications, for detailed NI 783xR specifications.

Using PXI with CompactPCI

Using PXI-compatible products with standard CompactPCI products is an important feature provided by PXI Hardware Specification Revision 2.1 and PXI Software Specification Revision 2.1. If you use a PXI-compatible plug-in card in a standard CompactPCI chassis, you cannot use PXI-specific functions, but you still can use the basic plug-in card functions. For example, the RTSI bus on the R Series device is available in a PXI chassis but not in a CompactPCI chassis.
The CompactPCI specification permits vendors to develop sub-buses that coexist with the basic PCI interface on the CompactPCI bus. Compatible operation is not guaranteed between CompactPCI devices with different sub-buses nor between CompactPCI devices with sub-buses and PXI. The standard implementation for CompactPCI does not include these sub-buses. The R Series device works in any standard CompactPCI chassis adhering to the PICMG CompactPCI 2.0 R3.0 core specification.
PXI-specific features are implemented on the J2 connector of the CompactPCI bus. Table 1-1 lists the J2 pins used by the NI 783xR. The NI 783xR is compatible with any CompactPCI chassis with a sub-bus that does not drive these lines. Even if the sub-bus is capable of driving these lines, the R Series device is still compatible as long as those pins on the sub-bus are disabled by default and are never enabled.
Caution Damage can result if the J2 lines are driven by the sub-bus.
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Chapter 1 Introduction

Table 1-1. Pins Used by the NI PXI-783xR

NI PXI-783xR Signal PXI Pin Name PXI J2 Pin Number
PXI Trigger<0..7> PXI Trigger<0..7> A16, A17, A18, B16, B18, C18,
E16, E18
PXI Clock 10 MHz PXI Clock 10 MHz E17
PXI Star Trigger PXI Star Trigger D17
LBLSTAR<0..12> LBL<0..12> A1, A19, C1, C19, C20, D1, D2,
D15, D19, E1, E2, E19, E20
LBR<0..12> LBR<0..12> A2, A3, A20, A21, B2, B20, C3,
C21, D3, D21, E3, E15, E21

Overview of Reconfigurable I/O

This section explains reconfigurable I/O and describes how to use the LabVIEW FPGA Module to build high-level functions in hardware.
Refer to Chapter 2, Hardware Overview of the NI 783x R, for descriptions of the I/O resources on the NI 783xR.

Reconfigurable I/O Concept

The NI 783xR is based on a reconfigurable FPGA core surrounded by fixed I/O resources for analog and digital input and output. You can configure the behavior of the reconfigurable FPGA to match the requirements of the measurement and control system. You can implement this user-defined behavior as an FPGA VI to create an application-specific I/O device.
Flexible Functionality
Flexible functionality allows the NI 783xR to match individual application requirements and to mimic the functionality of fixed I/O devices. For example, you can configure an R Series device in one application for three 32-bit quadrature encoders and then reconfigure the R Series device in another application for eight 16-bit event counters.
You also can use the R Series device with the LabVIEW Real-Time Module in timing and triggering applications, such as control and hardware-in-the-loop (HIL) simulations. For example, you can configure the R Series device for a single timed loop in one application and then reconfigure the device in another application for four independent timed loops with separate I/O resources.
© National Instruments Corporation 1-3 NI 783xR User Manual
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Chapter 1 Introduction
User-Defined I/O Resources
You can create your own custom measurements using the fixed I/O resources. For example, one application might require an event counter that increments when a rising edge appears on any of three digital input lines. Another application might require a digital line to be asserted after an analog input exceeds a programmable threshold.
Device-Embedded Logic and Processing
You can implement LabVIEW logic and processing in the FPGA of the R Series device. Typical logic functions include Boolean operations, comparisons, and basic mathematical operations. You can implement multiple functions efficiently in the same design, operating sequentially or in parallel. You also can implement more complex algorithms such as control loops. You are limited only by the size of the FPGA.

Reconfigurable I/O Architecture

Figure 1-1 shows an FPGA connected to fixed I/O resources and a bus interface. The fixed I/O resources include A/D converters (ADCs), D/A converters (DACs), and digital I/O lines.
Fixed I/O Resource
Fixed I/O Resource
FPGA
Bus Interface
Figure 1-1. High-Level FPGA Functional Overview
Fixed I/O Resource
Fixed I/O Resource
Software accesses the R Series device through the bus interface, and the FPGA connects the bus interface and the fixed I/O to make possible timing, triggering, processing, and custom I/O measurements using the LabVIEW FPGA Module.
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Chapter 1 Introduction
The FPGA logic provides timing, triggering, processing, and custom I/O measurements. Each fixed I/O resource used by the application uses a small portion of the FPGA logic that controls the fixed I/O resource. The bus interface also uses a small portion of the FPGA logic to provide software access to the device.
The remaining FPGA logic is available for higher-level functions such as timing, triggering, and counting. The functions use varied amounts of logic.
You can place useful applications in the FPGA. How much FPGA space your application requires depends on your need for I/O recovery, I/O, and logic algorithms.
The FPGA does not retain the VI when the R Series device is powered off, so you must reload the VI each time you power on the device. You can load the VI from onboard Flash memory or from software over the bus interface. One advantage to using Flash memory is that the VI can start executing almost immediately after power up, instead of waiting for the computer to completely boot and load the FPGA. Refer to the LabVIEW FPGA Module User Manual for more information about how to store your VI in Flash memory.

Reconfigurable I/O Applications

You can use the LabVIEW FPGA Module to create or acquire new VIs for your application. The FPGA Module allows you to define custom functionality for the R Series device using a subset of LabVIEW functionality. Refer to the FPGA Module examples located in the
<LabVIEW>\examples\FPGA directory for examples of FPGA VIs.

Software Development

You can use LabVIEW with the LabVIEW FPGA Module to program the NI 783xR. To develop real-time applications that control the NI 783xR, use LabVIEW with the LabVIEW Real-Time Module.

LabVIEW FPGA Module

The LabVIEW FPGA Module enables you to use LabVIEW to create VIs that run on the FPGA of the R Series device. Use the FPGA Module VIs and functions to control the I/O, timing, and logic of the R Series device and to generate interrupts for synchronization. Refer to the LabVIEW
FPGA Interface User Guide, available by selecting Start»Program Files»National Instruments»<LabVIEW>»Module Documents»
© National Instruments Corporation 1-5 NI 783xR User Manual
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Chapter 1 Introduction
FPGA Interface User Guide, for information about the FPGA Interface functions.
You can use Interactive Front Panel Communication to communicate directly with the VI running on the FPGA. You can use Programmatic FPGA Interface Communication to programmatically control and communicate with FPGA VIs from host VIs.
Use the FPGA Interface functions when you target LabVIEW for Windows or an RT target to create host VIs that wait for interrupts and control the FPGA by reading and writing the FPGA VI running on the R Series device.
Note If you use the R Series device without the FPGA Module, you can use the Download
VI or Attributes to Flash Memory utility available by selecting Start»Program Files» National Instruments»NI-RIO to download precomplied FPGA VIs to the Flash memory
of the R Series device. This utility is installed by the NI-RIO CD. You also can use the utility to configure the analog input mode, to synchronize the clock on the R Series device to the PXI clock (for NI PXI-783xR only), and to configure when the VI loads from Flash memory.

LabVIEW Real-Time Module

The LabVIEW Real-Time Module extends the LabVIEW development environment to deliver deterministic, real-time performance.
You can write host VIs that run in Windows or on RT targets to communicate with FPGA VIs that run on the NI 783xR. You can develop real-time VIs with LabVIEW and the LabVIEW Real-Time Module, and then download the VIs to run on a hardware target with a real-time operating system. The LabVIEW Real-Time Module allows you to use the NI 783xR in RT Series PXI systems being controlled in real time by a VI.
The NI 783xR is designed as a single-point AI, AO, and DIO complement to the LabVIEW Real-Time Module. Refer to the LabVIEW Real-Time Module User Manual and the LabVIEW Help, available by selecting Help»VI, Function, & How-To Help, for more information about the LabVIEW Real-Time Module.
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Cables and Optional Equipment

National Instruments offers a variety of products you can use with R Series devices, including cables, connector blocks, and other accessories, as shown in Table 1-2.

Table 1-2. Cables and Accessories

Cable Cable Description
NI 783xR
Connector
Chapter 1 Introduction
Accessories
SH68-C68-S Shielded 68-pin VHDCI
male connector to female
0.050 series D-type connector. The cable is constructed with 34 twisted wire pairs and an overall shield.
SHC68-68-RMIO Shielded 68-pin VHDCI
male connector to female
0.050 series D-type connector. The cable is constructed with individually shielded twisted-pairs for the analog input channels plus an additional shield around all the analog signals. This cable provides superior noise immunity on the MIO connector.
MIO or DIO Connects to the following
standard 68-pin screw terminal blocks:
• SCB-68
• CB-68LP
• CB-68LPR
•TBX-68
MIO only Connects to the following
standard 68-pin screw terminal blocks:
• SCB-68
• CB-68LP
• CB-68LPR
•TBX-68
© National Instruments Corporation 1-7 NI 783xR User Manual
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Chapter 1 Introduction
Cable Cable Description
Table 1-2. Cables and Accessories (Continued)
NI 783xR
Connector
Accessories
NSC68-262650 Non-shielded cable connects
from 68-pin VHDCI male connector to two 26-pin female headers plus one 50-pin female header. The pinout of these headers allows for direct connection to 5B backplanes for analog signal conditioning and SSR backplanes for digital signal conditioning.
NSC68-5050 Non-shielded cable connects
from 68-pin VHDCI male connector to two 50-pin female headers. The pinout of these headers allows for direct connection to SSR backplanes for digital signal conditioning.
MIO only 26-pin headers can connect
to the following 5B backplanes for analog signal conditioning:
• 5B08 (8-channel)
• 5B01 (16-channel)
50-pin header can connect to the following SSR backplanes for digital signal conditioning:
• 8-channel backplane
• 16-channel backplane
• 32-channel backplane
DIO only 50-pin headers can connect
to the following SSR backplanes for digital signal conditioning:
• 8-channel backplane
• 16-channel backplane
• 32-channel backplane
Refer to Appendix B, Connecting I/O Signals, for more information about using these cables and accessories to connect I/O signals to the NI 783xR. Refer to the most current cabling options.
ni.com/products or contact the sales office nearest to you for

Custom Cabling

NI offers a variety of cables for connecting signals to the NI 783xR. If you need to develop a custom cable, a nonterminated shielded cable is available from NI. The SHC68-NT-S connects to the NI 783xR VHDCI connectors on one end of the cable. The other end of the cable is not terminated. This cable ships with a wire list identifying the wires that correspond to each NI 783xR pin. Using this cable, you can quickly connect the NI 783xR
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Page 18
signals that you need to the connector of your choice. Refer to Appendix B,
Connecting I/O Signals, for the NI 783xR connector pinouts.

Safety Information

The following section contains important safety information that you must follow when installing and using the NI 783xR.
Do not operate the NI 783xR in a manner not specified in this document. Misuse of the NI 783xR can result in a hazard. You can compromise the safety protection built into the NI 783xR if the NI 783xR is damaged in any way. If the NI 783xR is damaged, return it to NI for repair.
Do not substitute parts or modify the NI 783xR except as described in this document. Use the NI 783xR only with the chassis, modules, accessories, and cables specified in the installation instructions. You must have all covers and filler panels installed during operation of the NI 783xR.
Do not operate the NI 783xR in an explosive atmosphere or where there might be flammable gases or fumes. If you must operate the NI 783xR in such an environment, it must be in a suitably rated enclosure.
Chapter 1 Introduction
If you need to clean the NI 783xR, use a soft, nonmetallic brush. Make sure that the NI 783xR is completely dry and free from contaminants before returning it to service.
Operate the NI 783xR only at or below Pollution Degree 2. Pollution is foreign matter in a solid, liquid, or gaseous state that can reduce dielectric strength or surface resistivity. The following is a description of pollution degrees:
Pollution Degree 1—No pollution or only dry, nonconductive pollution occurs. The pollution has no influence.
Pollution Degree 2—Only nonconductive pollution occurs in most cases. Occasionally, however, a temporary conductivity caused by condensation can be expected.
Pollution Degree 3—Conductive pollution occurs, or dry, nonconductive pollution occurs that becomes conductive due to condensation.
You must insulate signal connections for the maximum voltage for which the NI 783xR is rated. Do not exceed the maximum ratings for the NI 783xR. Do not install wiring while the NI 783xR is live with electrical signals. Do not remove or add connector blocks when power is connected
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Chapter 1 Introduction
to the system. Remove power from signal lines before connecting them to or disconnecting them from the NI 783xR.
Operate the NI 783xR at or below the measurement category
1
listed in the section Maximum working voltage, in Appendix A, Specifications. Measurement circuits are subjected to working voltages
2
and transient stresses (overvoltage) from the circuit to which they are connected during measurement or test. Measurement categories establish standard impulse withstand voltage levels that commonly occur in electrical distribution systems. The following list describes installation categories:
Measurement Category I—Measurements performed on circuits not
directly connected to the electrical distribution system referred to as MAINS
3
voltage. This category is for measurements of voltages from specially protected secondary circuits. Such voltage measurements include signal levels, special equipment, limited-energy parts of equipment, circuits powered by regulated low-voltage sources, and electronics.
Measurement Category II—Measurements performed on circuits
directly connected to the electrical distribution system. This category refers to local-level electrical distribution, such as that provided by a standard wall outlet (for example, 115 V for U.S. or 230 V for Europe). Examples of Installation Category II are measurements performed on household appliances, portable tools, and similar products.
Measurement Category III—Measurements performed in the
building installation at the distribution level. This category refers to measurements on hard-wired equipment such as equipment in fixed installations, distribution boards, and circuit breakers. Other examples are wiring, including cables, bus-bars, junction boxes, switches, socket-outlets in the fixed installation, and stationary motors with permanent connections to fixed installations.
Measurement Category IV—Measurements performed at the
primary electrical supply installation (<1,000 V). Examples include electricity meters and measurements on primary overcurrent protection devices and on ripple control units.
1
Measurement categories, also referred to as installation categories, are defined in electrical safety standard IEC 61010-1.
2
Working voltage is the highest rms value of an AC or DC voltage that can occur across any particular insulation.
3
MAINS is defined as a hazardous live electrical supply system that powers equipment. Suitably rated measuring circuits can be connected to the MAINS for measuring purposes.
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Hardware Overview of the NI 783x R
This chapter presents an overview of the hardware functions and I/O connectors on the NI 783xR.
Figure 2-1 shows a block diagram for the NI 7830R. Figure 2-2 shows a block diagram for the NI 7831R/7833R.
Calibration
DACs
x4 Channels
Temperature
Sensor
Calibration
DACs
Input Mode Mux
AISENSE AIGND
Calibration
Connector 0 (MIO)
AI+
AI–
Mux
Input Mux
Voltage
Reference
16-Bit
DAC
Digital I/O (16)
+
Instrumentation Amplifier
2
x4 Channels
16-Bit
ADC
User-
Configurable
FPGA on RIO
Devices
Configuration
Control
Configuration
Data/Address/
Control
Flash
Memory
Bus
Interface
2
Control
Address/Data
PCI/PXI/CompactPCI Bus
Digital I/O (40)
Connector 1 (DIO)
PXI Local Bus (NI PXI-783xR only)
RTSI Bus
RTSI/PXI Triggers

Figure 2-1. NI 7830R Block Diagram

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Chapter 2 Hardware Overview of the NI 783xR
Input Mux
Input Mode Mux
AISENSE AIGND
Calibration
Connector 0 (MIO)
Connector 1 (DIO)Connector 2 (DIO)
AI+
AI–
Mux
Digital I/O (16)
Digital I/O (40)
Voltage
Reference
16-Bit
DAC
+
Instrumentation Amplifier
2
x8 Channels
Calibration
DACs
x8 Channels
Temperature
Sensor
Calibration
DACs
16-Bit
ADC
User-
Configurable
FPGA on RIO
Devices
Configuration
Control
Configuration
Data/Address/
Control
PXI Local Bus (NI PXI-783xR only)
Flash
Memory
Bus
Interface
RTSI Bus
Control
Address/Data
PCI/PXI/CompactPCI Bus
Digital I/O (40)

Figure 2-2. NI 7831R/7833R Block Diagram

NI 7830R Overview

The NI 7830R has four independent, 16-bit AI channels; four independent, 16-bit AO channels; and 56 bidirectional DIO lines that you can configure individually for input or output.

NI 7831R/7833R Overview

The NI 7831R and NI 7833R each have eight independent, 16 bit AI channels; eight independent, 16-bit AO channels; and 96 bidirectional DIO lines that you can configure individually for input or output.

Analog Input

You can sample NI 783xR AI channels simultaneously or at different rates. The input mode is software configurable, and the input range is fixed at
RTSI/PXI Triggers
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Chapter 2 Hardware Overview of the NI 783xR
±10 V. The converters return data in two’s complement format. Table 2-1 shows the ideal output code returned for a given AI voltage.

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

Output Code (Hex)
Input Description AI Voltage
(Two’s Complement)
Full-scale range –1 LSB 9.999695 7FFF
Full-scale range –2 LSB 9.999390 7FFE
Midscale 0.000000 0000
Negative full-scale range +1 LSB –9.999695 8001
Negative full-scale range –10.000000 8000
Any input voltage
Output Code
----------------------------------
32,768
10.0 V×

Input Modes

The NI 783xR input mode is software configurable. The input channels support three input modes—differential (DIFF), referenced single ended (RSE), and nonreferenced single ended (NRSE). The selected input mode applies to all the input channels. Table 2-2 describes the three input modes.
Table 2-2. Available Input Modes for the NI 783xR
Input Mode Description
DIFF When the NI 783xR 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. The negative input pin connects to the negative input of the instrumentation amplifier.
RSE When the NI 783xR 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 connects internally to the AI ground (AIGND).
NRSE When the NI 783xR 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 connects internally to the AISENSE input pin.
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Chapter 2 Hardware Overview of the NI 783xR

Input Range

The NI 783xR AI range is fixed at ±10 V.

Connecting Analog Input Signals

The AI signals for the NI 783xR are AI<0..n>+, AI<0..n>–, AIGND, and AISENSE. For the NI 7830R, n=4. For the NI 7831R/7833R, n=8. The AI<0..n>+ and AI<0..n>– signals are connected to the eight AI channels of the NI 783xR. For all input modes, the AI<0..n>+ signals are connected to the positive input of the instrumentation amplifier on each channel. The signal connected to the negative input of the instrumentation amplifier depends on how you configure the input mode of the device.
In differential input mode, signals connected to AI<0..n>– are routed to the negative input of the instrumentation amplifier for each channel. In RSE input mode, the negative input of the instrumentation amplifier for each channel is internally connected to AIGND. In NRSE input mode, the AISENSE signal is connected internally to the negative input of the instrumentation amplifier for each channel. In DIFF and RSE input modes, AISENSE is not used.
Caution Exceeding the differential and common-mode input ranges distorts the input
signals. Exceeding the maximum input voltage rating can damage the NI 783xR and the computer. NI is not liable for any damage resulting from such signal connections. The maximum input voltage ratings are listed in Table B-2, NI 783xR I/O Signal Summary.
AIGND is a common AI signal that is routed directly to the ground tie point on the NI 783xR. You can use this signal for a general analog ground tie point to the NI 783xR if necessary.
Connection of AI signals to the NI 783xR depends on the input mode of the AI channels you are using and the type of input signal source. With different input modes, you can use the instrumentation amplifier in different ways. Figure 2-3 shows a diagram of the NI 783xR instrumentation amplifier.
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V
in+
V
in–
+
Instrumentation
Amplifier
V
= [V
m
in+
– V
in–
V
]
m
+
Measured
Voltage

Figure 2-3. NI 783xR Instrumentation Amplifier

The instrumentation amplifier applies common-mode voltage rejection and presents high input impedance to the AI signals connected to the NI 783xR. Input multiplexers on the device route signals to the positive and negative inputs of the instrumentation amplifier. The instrumentation amplifier converts two input signals to a signal that is the difference between the two input signals. The amplifier output voltage is referenced to the device ground. The NI 783xR ADC measures this output voltage when it performs A/D conversions.
You must reference all signals to ground either at the source device or at the NI 783xR. If you have a floating source, reference the signal to ground by using RSE input mode or the DIFF input mode with bias resistors. Refer to the Differential Connections for Nonreferenced or Floating Signal Sources section of this chapter for more information about these input modes. If you have a grounded source, do not reference the signal to AIGND. You can avoid this reference by using DIFF or NRSE input modes.
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Chapter 2 Hardware Overview of the NI 783xR

Types of Signal Sources

When configuring the input channels and making signal connections, you must first determine whether the signal sources are floating or ground referenced. The following sections describe these two signal types.

Floating Signal Sources

A floating signal source is not connected to the building ground system but instead has an isolated ground-reference point. Some examples of floating signal sources are outputs of transformers, thermocouples, battery-powered devices, optical isolator outputs, and isolation amplifiers. An instrument or device that has an isolated output is a floating signal source. You must connect the ground reference of a floating signal to the NI 783xR AIGND through a bias resistor to establish a local or onboard reference for the signal. Otherwise, the measured input signal varies as the source floats out of the common-mode input range.

Ground-Referenced Signal Sources

A ground-referenced signal source is connected to the building system ground, so it is already connected to a common ground point with respect to the NI 783xR, assuming that the computer is plugged into the same power system. Instruments or devices with nonisolated outputs that plug into the building power system are ground referenced signal sources.
The difference in ground potential between two instruments connected to the same building power system is typically between 1 and 100 mV. This difference can be much higher if power distribution circuits are improperly connected. If a grounded signal source is improperly measured, this difference might appear as a measurement error. The connection instructions for grounded signal sources are designed to eliminate this ground potential difference from the measured signal.

Input Modes

The following sections discuss single-ended and differential measurements and considerations for measuring both floating and ground-referenced signal sources.
Figure 2-4 summarizes the recommended input mode for both types of signal sources.
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Chapter 2 Hardware Overview of the NI 783xR
Signal Source Type
Input
Differential
(DIFF)
Single-Ended —
Ground
Referenced
(RSE)
Floating Signal Source
(Not Connected to Building Ground)
Examples
• Ungrounded Thermocouples
• Signal Conditioning with Isolated Outputs
• Battery Devices
+
V
1
AI<i>(+)
AI<
i
>(–)
AIGND<
+
i
>
See text for information on bias resistors.
+
V
AI<i>
1
AIGND<
+
i
>
Grounded Signal Source
Examples
• Plug-in Instruments with Nonisolated Outputs
+
V
AI<i>(+)
1
AI<
i
>(–)
+
AIGND<
NOT RECOMMENDED
+
V
AI
1
+ V
+
g
AIGND
i
>
Ground-loop losses, Vg, are added to
measured signal.
AI<i>
V
1
AISENSE
AIGND<
+
i
>
Single-Ended —
Nonreferenced
(NRSE)
AI<i>
AIGND<
+
i
>
+
V
1
AISENSE
+ –
See text for information on bias resistors.

Figure 2-4. Summary of Analog Input Connections

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Chapter 2 Hardware Overview of the NI 783xR

Differential Connection Considerations (DIFF Input Mode)

In DIFF input mode, the NI 783xR measures the difference between the positive and negative inputs. DIFF input mode is ideal for measuring ground-referenced signals from other devices. When using DIFF input mode, the input signal connects to the positive input of the instrumentation amplifier and its reference signal, or return, connects to the negative input of the instrumentation amplifier.
Use differential input connections for any channel that meets any of the following conditions:
The input signal is low level (less than 1 V).
The leads connecting the signal to the NI 783xR are greater than 3 m (10 ft).
The input signal requires a separate ground-reference point or return signal.
The signal leads travel through noisy environments.
Differential signal connections reduce noise pickup and increase common-mode noise rejection. Differential signal connections also allow input signals to float within the common-mode limits of the instrumentation amplifier.
Differential Connections for Ground-Referenced Signal Sources
Figure 2-5 shows how to connect a ground-referenced signal source to a channel on the NI 783xR configured in DIFF input mode.
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Ground-
Referenced
Signal
Source
Common-
Mode
Noise and
Ground
Potential
+
V
s
+
V
cm
I/O Connector
AI+
AI–
AISENSE
AIGND
DIFF Input Mode Selected
+
Instrumentation
Amplifier
V
m
+
Measured
Voltage
Figure 2-5. Differential Input Connections for Ground-Referenced Signals
With this connection type, the instrumentation amplifier rejects both the common-mode noise in the signal and the ground potential difference between the signal source and the NI 783xR ground, shown as V
cm
in Figure 2-5. In addition, the instrumentation amplifier can reject common-mode noise pickup in the leads connecting the signal sources to the device. The instrumentation amplifier can reject common-mode signals when V+
and V–in (input signals) are both within their specified input
in
ranges. Refer to Appendix A, Specifications, for more information about input ranges.
Differential Connections for Nonreferenced or Floating Signal Sources
Figure 2-6 shows how to connect a floating signal source to a channel on the NI 783xR configured in DIFF input mode.
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Chapter 2 Hardware Overview of the NI 783xR
Floating
Signal
Source
Bias
Current
Return
Paths
Bias
+
Resistors (see text)
V
s
I/O Connector
AI+
AI–
AISENSE
AIGND
DIFF Input Mode Selected
+
Instrumentation
Amplifier
V
m
+
Measured
Voltage
Figure 2-6. Differential Input Connections for Nonreferenced Signals
Figure 2-6 shows two bias resistors connected in parallel with the signal leads of a floating signal source. If you do not use the resistors and the source is truly floating, the source might not remain within the common-mode signal range of the instrumentation amplifier, causing erroneous readings. You must reference the source to AIGND by connecting the positive side of the signal to the positive input of the instrumentation amplifier and connecting the negative side of the signal to AIGND and to the negative input of the instrumentation amplifier without resistors. This connection works well for DC-coupled sources with low source impedance, less than 100 Ω.
For larger source impedances, this connection leaves the differential signal path significantly out of balance. Noise that couples electrostatically onto the positive line does not couple onto the negative line because it is connected to ground. Hence, this noise appears as a differential-mode signal instead of a common-mode signal, and the instrumentation amplifier does not reject it. In this case, instead of directly connecting the negative line to AIGND, connect it to AIGND through a resistor that is about 100 times the equivalent source impedance. The resistor puts the signal path nearly in balance. About the same amount of noise couples onto both connections, which yields better rejection of electrostatically coupled noise. Also, this input mode does not load down the source, other than the very high-input impedance of the instrumentation amplifier.
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You can fully balance the signal path by connecting another resistor of the same value between the positive input and AIGND, as shown in Figure 2-6. This fully balanced input mode offers slightly better noise rejection but has the disadvantage of loading down the source with the series combination (sum) of the two resistors. If, for example, the source impedance is 2 k and each of the two resistors is 100 k, the resistors load down the source with 200 k and produce a –1% gain error.
Both inputs of the instrumentation amplifier require a DC path to ground for the instrumentation amplifier to work. If the source is AC coupled (capacitively coupled), the instrumentation amplifier needs a resistor between the positive input and AIGND. If the source has low-impedance, choose a resistor that is large enough not to significantly load the source but small enough not to produce significant input offset voltage as a result of input bias current, typically 100 k to 1 M. In this case, connect the negative input directly to AIGND. If the source has high output impedance, balance the signal path as previously described using the same value resistor on both the positive and negative inputs. Loading down the source causes some gain error.

Single-Ended Connection Considerations

When an NI 783xR AI signal is referenced to a ground that can be shared with other input signals, it forms a single-ended connection. The input signal connects to the positive input of the instrumentation amplifier and the ground connects to the negative input of the instrumentation amplifier.
Chapter 2 Hardware Overview of the NI 783xR
You can use single-ended input connections for any input signal that meets the following conditions:
The input signal is high-level (>1 V).
The leads connecting the signal to the NI 783xR are less than 3m(10ft).
The input signal can share a common reference point with other signals.
Use DIFF input connections for greater signal integrity for any input signal that does not meet the preceding conditions.
You can configure the NI 783xR channels in software for RSE or NRSE input modes. Use the RSE input mode for floating signal sources. In this case, the NI 783xR provides the reference ground point for the external signal. Use the NRSE input mode for ground-referenced signal sources. In this case, the external signal supplies its own reference ground point and the NI 783xR should not supply one.
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In single-ended input modes, electrostatic and magnetic noise couples into the signal connections more than in differential input modes. The coupling is the result of differences in the signal path. Magnetic coupling is proportional to the area between the two signal conductors. Electrical coupling is a function of how much the electric field differs between the two conductors.
Single-Ended Connections for Floating Signal Sources (RSE Input Mode)
Figure 2-7 shows how to connect a floating signal source to a channel on the NI 783xR configured for RSE input mode.
Floating
Signal
Source
+
V
s
I/O Connector
AI+
AI–
AISENSE
AIGND
RSE Input Mode Selected
Figure 2-7. Single-Ended Input Connections for Nonreferenced or Floating Signals
+
Instrumentation
Amplifier
V
m
+
Measured
Voltage
Single-Ended Connections for Grounded Signal Sources (NRSE Input Mode)
To measure a grounded signal source with a single-ended input mode, you must configure the NI 783xR in the NRSE input mode. Then connect the signal to the positive input of the NI 783xR instrumentation amplifier and connect the signal local ground reference to the negative input of the instrumentation amplifier. The ground point of the signal should be connected to AISENSE. Any potential difference between the NI 783xR ground and the signal ground appears as a common-mode signal at both the
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positive and negative inputs of the instrumentation amplifier. The instrumentation amplifier rejects this difference. If the input circuitry of a NI 783xR is referenced to ground in RSE input mode, this difference in ground potentials appears as an error in the measured voltage.
Figure 2-8 shows how to connect a grounded signal source to a channel on the NI 783xR configured for NRSE input mode.
Ground-
Referenced
Signal
Source
Common-
Mode
Noise and
Ground
Potential
+
V
s
+
V
cm
I/O Connector
AI+
AI–
AISENSE
AIGND
NRSE Input Mode Selected
+
Instrumentation
Amplifier
Figure 2-8. Single-Ended Input Connections for Ground-Referenced Signals

Common-Mode Signal Rejection Considerations

Figure 2-5 and Figure 2-8 show connections for signal sources that are already referenced to some ground point with respect to the NI 783xR. In these cases, the instrumentation amplifier can reject any voltage caused by ground potential differences between the signal source and the device. With differential input connections, the instrumentation amplifier can reject common-mode noise pickup in the leads connecting the signal sources to the device. The instrumentation amplifier can reject common-mode signals when V+ their specified input ranges. Refer to Appendix A, Specifications, for more information about input ranges.
and V–in (input signals) are both within
in
V
m
+
Measured
Voltage
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Chapter 2 Hardware Overview of the NI 783xR

Analog Output

The bipolar output range of the NI 783xR AO channels is fixed at ±10 V. Some applications require that the AO channels power on to known voltage levels. To set the power-on levels, you can configure the NI 783xR to load and run a VI when the system powers on. The VI can set the AO channels to the desired voltage levels. The VI interprets data written to the DAC in two’s complement format. Table 2-3 shows the ideal AO voltage generated for a given input code.

Table 2-3. Ideal Output Voltage and Input Code Mapping

Input Code (Hex)
Output Description AO Voltage
Full-scale range –1 LSB 9.999695 7FFF
Full-scale range –2 LSB 9.999390 7FFE
Midscale 0.000000 0000
(Two’s Complement)
Negative full-scale range, +1 LSB
Negative full-scale range –10.000000 8000
Any output voltage
Note If your VI does not set the output value for an AO channel, then the AO channel
voltage output will be undefined.
–9.999695 8001
AO Voltage
-------------------------------
10.0 V

Connecting Analog Output Signals

The AO signals are AO <0..n> and AOGND.
AO <0..n> are the AO channels. AOGND is the ground reference signal for the AO channels.
Figure 2-9 shows how to make AO connections to the NI 783xR.
32,768×
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Chapter 2 Hardware Overview of the NI 783xR
+
Load
VOUT 0

Figure 2-9. Analog Output Connections

Digital I/O

You can configure the NI 783xR DIO lines individually for either input or output. When the system powers on, the DIO lines are high impedance. To set another power-on state, you can configure the NI 783xR to load a VI when the system powers on. The VI can then set the DIO lines to any power-on state.

Connecting Digital I/O Signals

AO0
AOGND0
NI 783
x
R
Channel 0
The DIO signals on the NI 783xR MIO connector are DGND and DIO<0..15>. The DIO signals on the NI 783xR DIO connector are DGND and DIO<0..39>. The DIO<0..n> signals make up the DIO port and DGND is the ground reference signal for the DIO port. The NI 7830R has one MIO and one DIO connector for a total of 56 DIO lines. The NI 7831R/7833R has one MIO and two DIO connectors for a total of 96 DIO lines.
Refer to Figure B-1, NI 783xR Connector Locations, and Figure B-2,
NI 783x R I/O Connector Pin Assignments, for the connector locations and
the I/O connector pin assignments on the NI 783xR.
The DIO lines on the NI 783xR are TTL-compatible. When configured as inputs, they can receive signals from 5 V TTL, 3.3 V LVTTL, 5 V CMOS, and 3.3 V LVCMOS devices. When configured as outputs, they can send signals to 5 V TTL, 3.3 V LVTTL, and 3.3 V LVCMOS devices. Because the digital outputs provide a nominal output swing of 0 to 3.3 V
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Chapter 2 Hardware Overview of the NI 783xR
(3.3 V TTL), the DIO lines cannot drive 5 V CMOS logic levels. To interface to 5 V CMOS devices, you must provide an external pull-up resistor to 5 V. This resistor pulls up the 3.3 V digital output from the NI 783xR to 5 V CMOS logic levels. Refer to Appendix A, Specifications, for detailed DIO specifications.
Caution Exceeding the maximum input voltage ratings, listed in Table B-2, NI 783xR I/O
Signal Summary, can damage the NI 783xR and the computer. NI is not liable for any
damage resulting from such signal connections.
Caution Do not short the DIO lines of the NI 783xR directly to power or to ground. Doing
so can damage the NI 783xR by causing excessive current to flow through the DIO lines.
You can connect multiple NI 783xR digital output lines in parallel to provide higher current sourcing or sinking capability. If you connect multiple digital output lines in parallel, your application must drive all of these lines simultaneously to the same value. If you connect digital lines together and drive them to different values, excessive current can flow through the DIO lines and damage the NI 783xR. Refer to Appendix A,
Specifications, for more information about DIO specifications. Figure 2-10
shows signal connections for three typical DIO applications.
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LED
5 V CMOS
DGND
+5 V
TTL or LVCMOS Compatible Devices
Chapter 2 Hardware Overview of the NI 783xR
*
DIO<4..7>
TTL, LVTTL, CMOS, or LVCMOS Signal
+5 V
Switch
I/O Connector
*
3.3 V CMOS
Use a pull-up resistor when driving 5 V CMOS devices.

Figure 2-10. Example Digital I/O Connections

Figure 2-10 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 Figure 2-10. Digital output applications include sending TTL or LVCMOS signals and driving external devices, such as the LED shown in Figure 2-10.
DGND
NI 783
DIO<0..3>
x
R
The NI 783xR SH68-C68-S shielded cable contains 34 twisted pairs of conductors. To maximize the digital I/O available on the NI 783xR, 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 paired with power or ground. Because the DIO lines that are twisted with other DIO lines can couple noise onto each other, use these lines for static
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Chapter 2 Hardware Overview of the NI 783xR
signals or non-edge-sensitive, low-frequency digital signals. Examples of high-frequency or edge-sensitive signals include clock, trigger, pulse-width modulation (PWM), encoder, and counter signals. Examples of static signals or non-edge-sensitive, low-frequency signals include LEDs, switches, and relays. Table 2-4 summarizes these guidelines.

Table 2-4. DIO Signal Guidelines for the NI 783xR

Digital Lines
Connector 0, DIO<0..7>; Connector 1, DIO<0..27>; Connector 2, DIO<0..27>
Connector 0, DIO<8..15>; Connector 1, DIO<28..39>; Connector 2, DIO<28..39>

RTSI Trigger Bus

The NI 783xR can send and receive triggers through the RTSI trigger bus. The RTSI bus provides eight shared triggers lines that connect to all the devices on the bus. In PXI, the trigger lines are shared between all the PXI slots in a bus segment. In PCI, the RTSI bus is implemented through a ribbon cable connected to the RTSI connector on each device that needs to access the RTSI bus.
You can use the RTSI trigger lines to synchronize the NI 783xR to any other device that supports RTSI triggers. On the NI PCI-783xR, the RTSI trigger lines are labeled RTSI/TRIG<0..6> and RTSI/OSC. On the NI PXI-783xR, the RTSI trigger lines are labeled PXI/TRIG<0..7>. In addition, the NI PXI-783xR can use the PXI star trigger line to send or receive triggers from a device plugged into Slot 2 of the PXI chassis. The PXI star trigger line on the NI PXI-783xR is PXI/STAR.
SH68-C68-S Shielded Cable
Signal Pairing
DIO line paired with power or ground
DIO line paired with another DIO line
Recommended Types
of Digital Signals
All types—high-frequency or low-frequency signals, edge-sensitive or non-edge-sensitive signals
Static signals or non-edge-sensitive, low-frequency signals
The NI 783xR can configure each RTSI trigger line either as an input or an output signal. Because each trigger line on the RTSI bus is connected in parallel to all the other RTSI devices on the bus, only one device should drive a particular RTSI trigger line at a time. For example, if one NI PXI-783xR is configured to send out a trigger pulse on PXI/TRIG0, the remaining devices on that PXI bus segment must have PXI/TRIG0 configured as an input.
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Chapter 2 Hardware Overview of the NI 783xR
Caution Do not drive the same RTSI trigger bus line with the NI 783xR and another device
simultaneously. Such signal driving can damage both devices. NI is not liable for any damage resulting from such signal driving.
For more information on using and configuring triggers, select Help»VI, Function, & How-To Help in LabVIEW to view the LabVIEW Help. Refer to the PXI Hardware Specification Revision 2.1 and PXI Software Specification Revision 2.1 at PXI triggers.
www.pxisa.org for more information about

PXI Local Bus (for NI PXI-783xR only)

The NI PXI-783xR can communicate with other PXI devices using the PXI local bus. The PXI local bus is a daisy-chained bus that connects each PXI peripheral slot with its adjacent peripheral slot on either side. For example, the right local bus lines from a PXI peripheral slot connect to the left local bus lines of the adjacent slot on the right. Each local bus is 13 lines wide. All of these lines connect to the FPGA on the NI PXI-783xR. The PXI local bus right lines on the NI PXI-783xR are PXI/LBR<0..12>. The PXI local bus left lines on the NI PXI-783xR are PXI/LBLSTAR<0..12>.
The NI PXI-783xR can configure each PXI local bus line either as an input or an output signal. Only one device can drive the same physical local bus line at a time. For example, if the NI PXI-783xR is configured to drive a signal on PXI/LBR 0, the device in the slot immediately to the right must have its PXI/LBLSTAR 0 line configured as an input.
Caution Do not drive the same PXI local bus line with the NI PXI-783xR and another
device simultaneously. Such signal driving can damage both devices. NI is not liable for any damage resulting from such signal driving.
The NI PXI-783xR local bus lines are only compatible with 3.3 V signaling LVTTL and LVCMOS levels.
Caution Do not enable the local bus lines on an adjacent device if the device drives
anything other than 0–3.3V LVTTL signal levels on the NI PXI-783xR. Enabling the lines in this way can damage the NI PXI-783xR. NI is not liable for any damage resulting from enabling such lines.
The left local bus lines from the left peripheral slot of a PXI backplane (Slot 2) are routed to the star trigger lines of up to 13 other peripheral slots in a two-segment PXI system. This configuration provides a dedicated,
© National Instruments Corporation 2-19 NI 783xR User Manual
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Chapter 2 Hardware Overview of the NI 783xR
delay-matched trigger signal between the first peripheral slot and the other peripheral slots for precise trigger timing signals. For example, an NI PXI-783xR in Slot 2 can send an independent trigger signal to each device plugged into Slots <3..15> using the PXI/LBLSTAR<0..12>. Each device receives its trigger signal on its own dedicated star trigger line.
Caution Do not configure the NI 783xR and another device to drive the same physical star
trigger line simultaneously. Such signal driving can damage the NI 783xR and the other device. NI is not liable for any damage resulting from such signal driving.
Refer to the PXI Hardware Specification Revision 2.1 and PXI Software Specification Revision 2.1 at PXI triggers.

Switch Settings

Refer to Figure 2-11 for the location of switches on the NI PXI-783xR and Figure 2-12 for the location of switches on the NI PCI-783xR. For normal operation, SW1 is in the OFF position. To prevent a VI stored in Flash memory from loading to the FPGA at power up, move SW1 to the ON position, as shown in Figure 2-13. SW2 and SW3 are not connected.
www.pxisa.org for more information about
NI 783xR User Manual 2-20 ni.com
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Chapter 2 Hardware Overview of the NI 783xR
SW1, SW2, SW3

Figure 2-11. Switch Location on the NI PXI-783xR

© National Instruments Corporation 2-21 NI 783xR User Manual
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Chapter 2 Hardware Overview of the NI 783xR
SW1, SW2, SW3

Figure 2-12. Switch Location on the NI PCI-783xR

ON
123
a. Normal Operation (Default)

Figure 2-13. Switch Settings

b. Prevent VI From Loading
ON
123
Complete the following steps to prevent a VI stored in Flash memory from loading to the FPGA:
1. Power off and unplug the PXI/CompactPCI chassis or PCI computer.
2. Remove the NI 783xR from the PXI/CompactPCI chassis or PCI computer.
3. Move SW1 to the ON position, as shown in Figure 2-13b.
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4. Reinsert the NI 783xR into the PXI/CompactPCI chassis or PCI computer. Refer to the Installing the Hardware section of the Getting Started with the NI 783xR document for installation instructions.
5. Plug in and power on the PXI/CompactPCI chassis or PCI computer.
After completing this procedure, a VI stored in Flash memory does not load to the FPGA at power-on. You can use software to configure the NI 783xR if necessary. To return to the defaults of loading from Flash memory, repeat the previous procedure but return SW1 to the OFF position in step 3. You can use this switch to enable/disable the ability to load from Flash memory. In addition to this switch, you must configure the NI 783xR with the software to autoload an FPGA VI.
Note When the NI 783xR is powered on with SW1 in the ON position, the analog circuitry
does not return properly calibrated data. Move the switch to the ON position only while you are using software to reconfigure the NI 783xR for the desired power-up behavior. Afterward, return SW1 to the OFF position.

Power Connections

Two pins on each I/O connector supply 5 V from the computer power supply using a self-resetting fuse. The fuse resets automatically within a few seconds after the overcurrent condition is removed. The +5V pins are referenced to DGND and can power external digital circuitry. The NI 783xR has the following power rating:
Chapter 2 Hardware Overview of the NI 783xR
+4.50 to +5.25 VDC at 1 A (250 mA max per +5V pin, 1 A max total for all +5V lines on the device)
Caution Do not connect the +5V power pins directly to analog or digital ground or to any
other voltage source on the NI 783xR or any other device under any circumstance. Doing so can damage the NI 783xR and the computer. NI is not liable for damage resulting from such a connection.
© National Instruments Corporation 2-23 NI 783xR User Manual
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Chapter 2 Hardware Overview of the NI 783xR

Field Wiring Considerations

Environmental noise can seriously affect the measurement accuracy of the device if you do not take proper care when running signal wires between signal sources and the device. The following recommendations mainly apply to AI signal routing to the device. They also apply to signal routing in general.
Take the following precautions to minimize noise pickup and maximize measurement accuracy:
Use differential AI connections to reject common-mode noise.
Use individually shielded, twisted-pair wires to connect AI signals to the device. With this type of wire, the signals attached to the positive and negative inputs are twisted together and then covered with a shield. You then connect this shield only at one point to the signal source ground. This kind of connection is required for signals traveling through areas with large magnetic fields or high electromagnetic interference.
Route signals to the device carefully. Keep cabling away from noise sources. The most common noise source in a PXI DAQ system is the video monitor. Keep the monitor and the analog signals as far apart as possible.
Use the following recommendations for all signal connections to the NI 783xR:
Separate NI 783xR signal lines from high-current or high-voltage lines. These lines can induce currents in or voltages on the NI 783xR signal lines if they run in parallel paths at a close distance. To reduce the magnetic coupling between lines, separate them by a reasonable distance if they run in parallel or run the lines at right angles to each other.
•Do not run signal lines through conduits that also contain power lines.
Protect signal lines from magnetic fields caused by electric motors, welding equipment, breakers, or transformers by running them through special metal conduits.
Refer to the NI Developer Zone tutorial, Field Wiring and Noise Considerations for Analog Signals, at
NI 783xR User Manual 2-24 ni.com
ni.com/zone for more information.
Page 44
Calibration
Calibration is the process of determining and/or adjusting the accuracy of an instrument to minimize measurement and output voltage errors. On the NI 783xR, onboard calibration DACs (CalDACs) correct these errors. Because the analog circuitry handles calibration, the data read from the AI channels or written to the AO channels in the FPGA VI is already calibrated.
Three levels of calibration are available for the NI 783xR to ensure the accuracy of its analog circuitry. The first level, loading calibration constants, is the fastest, easiest, and least accurate. The intermediate level, internal calibration, is the preferred method of assuring accuracy in your application. The last level, external calibration, is the slowest, most difficult, and most accurate.

Loading Calibration Constants

The NI 783xR is factory calibrated before shipment at approximately 25 °C to the levels indicated in Appendix A, Specifications. The onboard nonvolatile Flash memory stores the calibration constants for the device. Calibration constants are the values that were written to the CalDACs to achieve calibration in the factory. The NI 783xR hardware reads these constants from the Flash memory and loads them into the CalDACs at power-on. This occurs before you load a VI into the FPGA.
3

Internal Calibration

With internal calibration, the NI 783xR can measure and correct almost all of its calibration-related errors without any external signal connections. NI provides software to perform an internal calibration. This internal calibration process, which generally takes less than two minutes, is the preferred method of assuring accuracy in your application. Internal calibration minimizes the effects of any offset and gain drifts, particularly those due to changes in temperature. During the internal calibration process, the AI and AO channels are compared to the NI 783xR onboard voltage reference. The offset and gain errors in the analog circuitry are calibrated out by adjusting the CalDACs to minimize these errors.
© National Instruments Corporation 3-1 NI 783xR User Manual
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Chapter 3 Calibration
If you have NI-RIO installed, you can find the internal calibration utility at
Start»All Programs»National Instruments»NI-RIO»device»Calibrate 783xR Device. Device is the NI PXI-783xR or NI PCI-783xR device.
Immediately after internal calibration, the only significant residual calibration error is gain error due to time and temperature drift of the onboard voltage reference. You can minimize gain errors by performing an external calibration. If you are primarily taking relative measurements, then you can ignore a small amount of gain error and self-calibration is sufficient.
The Flash memory on the NI 783xR stores the results of an internal calibration so the CalDACs automatically load with the newly calculated calibration constants the next time the NI 783xR is powered on.

External Calibration

An external calibration refers to calibrating your device with a known external reference rather than relying on the onboard reference. The NI 783xR has an onboard calibration reference to ensure the accuracy of self-calibration. The reference voltage is measured at the factory and stored in the Flash memory for subsequent internal calibrations. Externally calibrate the device annually or more often if you use it at extreme temperatures.
During the external calibration process, the onboard reference value is re-calculated. This compensates for any time or temperature drift-related errors in the onboard reference that might have occurred since the last calibration. You can save the results of the external calibration process to Flash memory so that the NI 783xR loads the new calibration constants the next time it is powered on. The device uses the newly measured onboard reference level for subsequent internal calibrations.
To externally calibrate your device, use an external reference several times more accurate than the device itself.
NI 783xR User Manual 3-2 ni.com
Page 46
Specifications
This appendix lists the specifications of the NI 783xR. These specifications are typical at 25 °C unless otherwise noted.
Analog Input
Input Characteristics
Number of channels
NI 7830R......................................... 4
NI 7831R......................................... 8
NI 7833R......................................... 8
Input modes............................................ DIFF, RSE, NRSE
Type of ADC.......................................... Successive approximation
Resolution .............................................. 16 bits, 1 in 65,536
A
(software-selectable; selection applies to all channels)
Conversion time .....................................4
Maximum sampling rate ........................ 200 kS/s (per channel)
Input impedance
Powered on ..................................... 10 G in parallel with 100 pF
Powered off..................................... 4 k min
Overload..........................................4 k min
Input signal range................................... ±10 V
Input bias current ................................... ±2nA
Input offset current.................................±1nA
Input coupling ........................................ DC
© National Instruments Corporation A-1 NI 783xR User Manual
µs
Page 47
Appendix A Specifications
Maximum working voltage
(signal + common mode)........................Inputs should remain
within ±12 V of ground
Overvoltage protection ...........................±42 V
Data transfers..........................................Interrupts, programmed I/O
Accuracy Information
Relative
Absolute Accuracy
Noise +
Quantization
Nominal Range (V)
Positive
Full
Scale
10.0 –10.0 0.0496 0.0507 2542 1779 165 0.0005 7.78 2170 217
Note: Accuracies are valid for measurements following an internal calibration. Measurement accuracies are listed for operational temperatures within temperature. Temp drift applies only if ambient is greater than
Negative
Full
Scale
% of Reading
24
Hours
1 Year
Offset
(µV)
±1 °C of internal calibration temperature and ±10 °C of external or factory-calibration
(µV)
Te mp
Single
Point
Averaged
Drift
(%/°C)
±10 °C of previous external calibration.
Absolute
Accuracy
at Full
Scale
(
±mV)
Accuracy
Resolution (µV)
Single
Point
Averaged
DC Transfer Characteristics
INL..........................................................±3 LSB typ, ±6 LSB max
DNL ........................................................–1.0 to +2.0 LSB max
No missing codes resolution...................16 bits typ, 15 bits min
CMRR, DC to 60 Hz ..............................86 dB
Dynamic Characteristics
Bandwidth
Small signal (–3 dB)........................650 kHz
Large signal (1% THD) ...................55 kHz
System noise ...........................................1.8 LSB
(including quantization)
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rms
Page 48
Settling Time
Appendix A Specifications
Accuracy
Analog Output
Step Size
±20.0 V 7.5 µs 10.3 µs 40 µs
±2.0 V 2.7 µs 4.1 µs 5.1 µs
±0.2 V 1.7 µs 2.9 µs 3.6 µs
Crosstalk................................................. –80 dB, DC to 100 kHz
16 LSB 4LSB 2LSB
Output Characteristics
Output type............................................. Single-ended, voltage output
Number of channels
NI 7830R......................................... 4
NI 7831R......................................... 8
NI 7833R......................................... 8
Resolution .............................................. 16 bits, 1 in 65,536
Update time ............................................ 1.0 µs
Max update rate...................................... 1 MS/s
Type of DAC.......................................... Enhanced R-2R
Data transfers ......................................... Interrupts, programmed I/O
© National Instruments Corporation A-3 NI 783xR User Manual
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Appendix A Specifications
Accuracy Information
Absolute Accuracy
Nominal Range (V)
Positive Full
Scale
10.0 –10.0 0.0335 0.0351 2366 0.0005 5.88
Note: Accuracies are valid for analog output following an internal calibration. Analog output accuracies are listed for operation temperatures within temperature. Temp Drift applies only if ambient is greater than
Negative Full
Scale
±1 °C of internal calibration temperature and ±10 °C of external or factory calibration
% of Reading
24 Hours 1 Year
±10 °C of previous external calibration.
Offset (µV)
Temp Drift
(%/°C)
Absolute
Accuracy at
Full Scale
DC Transfer Characteristics
INL..........................................................±0.5 LSB typ, ±4.0 LSB max
DNL ........................................................±0.5 LSB typ, ±1 LSB max
Monotonicity ..........................................16 bits, guaranteed
Voltage Output
Range ......................................................±10 V
(mV)
Output coupling ......................................DC
Output impedance...................................1.25
Current drive...........................................±2.5 mA
Protection................................................Short-circuit to ground
Power-on state ........................................User configurable
Dynamic Characteristics
Settling time
Accuracy
Step Size
±20.0 V 6.0 µs 6.2 µs 7.2 µs
±2.0 V 2.2 µs 2.9 µs 3.8 µs
±0.2 V 1.5 µs 2.6 µs 3.6 µs
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16 LSB 4LSB 2LSB
Page 50
Slew rate................................................. 10 V/µs
Appendix A Specifications
Digital I/O
Noise ......................................................150
µV
, DC to 1 MHz
rms
Glitch energy
at midscale transition ............................. ±200 mV for 3
Number of channels
NI 7830R......................................... 56
NI 7831R......................................... 96
NI 7833R......................................... 96
Compatibility ......................................... TTL
Digital logic levels
Level Min Max
Input low voltage (VIL)
Input high voltage (V
)
IH
Output low voltage (VOL), where I
Output high voltage (V where I
OUT
OUT
= –I
= I
max
max
(sink)
OH
(source)
),
0.0 V
2.0 V
2.4 V
µs
0.8 V
5.5 V
0.4 V
Maximum output current
I
(source)..................................... 5.0 mA
max
I
(sink) ........................................ 5.0 mA
max
Input leakage current.............................. ±10 µA
Power-on state........................................ Programmable, by line
Data transfers ......................................... Interrupts, programmed I/O
Protection
Input ................................................ –0.5 to 7.0 V
Output ............................................. Short-circuit (up to eight lines
may be shorted at a time)
© National Instruments Corporation A-5 NI 783xR User Manual
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Appendix A Specifications
Reconfigurable FPGA
Number of logic slices
Equivalent number of logic cells
Available embedded RAM
Timebase.................................................40, 80, 120, 160, or 200 MHz
Timebase reference sources
NI 7830R .........................................5,120
NI 7831R .........................................5,120
NI 7833R .........................................14,336
NI 7830R .........................................11,520
NI 7831R .........................................11,520
NI 7833R .........................................32,256
NI 7830R .........................................81,920 bytes
NI 7831R .........................................81,920 bytes
NI 7833R .........................................196,608 bytes
NI PCI-783xR..................................Onboard clock only
NI PXI-783xR..................................Onboard clock, phase-locked to
PXI 10 MHz clock
Timebase accuracy
Onboard clock .................................±100 ppm, 250 ps jitter
Phase locked to PXI 10 MHz
Clock (NI PXI-783xR only) ...................Adds 350 ps jitter, 300 ps skew
Additional frequency dependent jitter
40 MHz............................................None
80 MHz............................................400 ps
120 MHz..........................................720 ps
160 MHz..........................................710 ps
200 MHz..........................................700 ps
Calibration
Recommended warm-up time.................15 minutes
Calibration interval .................................1 year
NI 783xR User Manual A-6 ni.com
Page 52
Note Refer to Calibration Certificates at ni.com/calibration to generate a
calibration certificate for the NI 783xR.
Bus Interface
Power Requirement
Appendix A Specifications
Onboard calibration reference
DC level ..........................................5.000 V (±3.5 mV)
(actual value stored in Flash memory)
Temperature coefficient.................. ±5 ppm/°C max
Long-term stability ......................... ±20 ppm/
1,000 h
PXI (NI PXI-783xR only) ...................... Master, slave
PCI (NI PCI-783xR only) ...................... Master, slave
+5 VDC (±5%)
NI 7830R......................................... 330 mA (typ), 355 mA (max)
NI 7831R......................................... 330 mA (typ), 355 mA (max)
NI 7833R......................................... 364 mA (typ), 586 mA (max)
1
1
1
+3.3 VDC (±5%)
NI 7830R......................................... 462 mA (typ), 660 mA (max)
NI 7831R......................................... 462 mA (typ), 660 mA (max)
NI 7833R......................................... 727 mA (typ), 1,148 mA (max)
2
2
2
To calculate the total current sourced by the digital outputs use the following equation:
j
current sourced on channel
i 1=
i
Where j is the number of digital outputs being used to source current.
Power available at I/O connectors ......... 4.50 to 5.25 VDC at 1 A total,
250 mA per I/O connector pin
1
Does not include current drawn form the +5 V line on the I/O connectors.
2
Does not include current sourced by the digital outputs.
© National Instruments Corporation A-7 NI 783xR User Manual
Page 53
Appendix A Specifications
Physical
Dimensions (not including connectors)
NI PXI-783xR..................................16 cm by 10 cm (6.3 in. by 3.9 in.)
NI PCI-783xR..................................17 cm by 11 cm (6.7 in. by 4.3 in.)
I/O connectors.........................................Three 68-pin female high-density
Maximum Working Voltage
Maximum working voltage refers to the signal voltage plus the common-mode voltage.
Channel-to-earth .....................................±12 V, Measurement Category I
Channel-to-channel.................................±24 V, Measurement Category I
Caution Do not use the NI 783xR for connection to signals in Measurement Categories II,
III, or IV.
Environmental
The NI 783xR is intended for indoor use only.
VHDCI type
Operating Environment
NI 7830R, NI 7831R
40 MHz or 80 MHz timebase ..........0 °C to 55 °C, tested in
accordance with IEC-60068-2-1 and IEC-60068-2-2
NI 7833R
40 MHz timebase.............................0 °C to 55 °C, tested in
accordance with IEC-60068-2-1 and IEC-60068-2-2
80 MHz timebase.............................0 °C to 55 °C except the
following: 0 °C to 45 °C when installed in an NI PXI-1000/B or NI PXI-101X; tested in accordance with IEC-60068-2-1 and IEC-60068-2-2
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Page 54
Appendix A Specifications
Relative humidity range ......................... 10% to 90%, noncondensing,
tested in accordance with IEC-60068-2-56
Altitude................................................... 2,000 m at 25 °C ambient
temperature
Storage Environment
Ambient temperature range.................... –20 °C to 70 °C tested in
accordance with IEC-60068-2-1 and IEC-60068-2-2
Relative humidity range ......................... 5% to 95%, noncondensing,
tested in accordance with IEC-60068-2-56
Note Clean the device with a soft, non-metallic brush. Make sure that the device is
completely dry and free from contaminants before returning it to service.
Shock and Vibration (for NI PXI-783x R Only)
Operational Shock..................................30 g peak, half-sine, 11 ms pulse
Tested in accordance with IEC-60068-2-27. Test profile developed in accordance with MIL-PRF-28800F.
Random Vibration
Operating ........................................ 5 Hz to 500 Hz, 0.3 g
Nonoperating .................................. 5 Hz to 500 Hz, 2.4 g
rms
rms
Tested in accordance with IEC-60068-2-64. Nonoperating test profile exceeds the requirements of MIL-PRF-28800F, Class 3.
© National Instruments Corporation A-9 NI 783xR User Manual
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Appendix A Specifications
Safety
The NI 783xR is designed to meet the requirements of the following standards of safety for electrical equipment for measurement, control, and laboratory use:
IEC 61010-1, EN 61010-1
UL 61010-1
CAN/CSA-C22.2 No. 61010-1
Note Refer to the product label, or visit ni.com/certification, search by model
number or product line, and click the appropriate link in the Certification column for UL and other safety certifications.
Electromagnetic Compatibility
Emissions................................................EN 55011 Class A at 10 m
Immunity ................................................EN 61326:1997 + A2: 2001,
EMC/EMI ...............................................CE, C-Tick, and FCC Part 15
FCC Part 15A above 1 GHz
Table 1
(Class A) compliant
Note For full EMC compliance, operate this device with shielded cabling.
CE Compliance
This product meets the essential requirements of applicable European Directives, as amended for CE marking, as follows:
Low-Voltage Directive (safety)..............73/23/EEC
Electromagnetic Compatibility
Directive (EMC) .....................................89/336/EEC
Note Refer to the Declaration of Conformity (DoC) for this product for any additional
regulatory compliance information. Visit number or product line, and click the appropriate link in the Certification column to obtain the DoC for this product.
NI 783xR User Manual A-10 ni.com
ni.com/certification, search by model
Page 56
Connecting I/O Signals
This appendix describes how to make input and output signal connections to the NI 783xR I/O connectors.
Figure B-1 shows the I/O connector locations for the NI PXI-7831R/7833R and the NI PCI-7831R/7833R. The NI PXI-7830R and NI PCI-7830R do not have Connector 2 (DIO).
CONNECTOR 0 (MIO)
B
CONNECTOR 0 (MIO)
CONNECTOR 1 (DIO)

Figure B-1. NI 783xR Connector Locations

© National Instruments Corporation B-1 NI 783xR User Manual
CONNECTOR 2 (DIO)
CONNECTOR 1 (DIO)
CONNECTOR 2 (DIO)
Page 57
Appendix B Connecting I/O Signals
Figure B-2 shows the I/O connector pin assignments for the I/O connectors on the NI 783xR. The DIO connector pin assignment applies to connector 1 on the NI 7830R and connectors <1..2> on the NI 7831R/7833R.
DIO39
DIO37
DIO35
DIO33
DIO31
DIO29
DIO27
DIO26
DIO25 DIO24 DIO23
DIO22
DIO21
DIO20
DIO19
DIO18
DIO17
DIO16
DIO15 DIO14
DIO13
DIO12
DIO11
DIO10
DIO9
DIO8
DIO7
DIO6
DIO5 DIO4
DIO3
DIO2
DIO1
DIO0
68 34
67 33
66 32
65 31
64 30
63 29
62 28
61 27
60 26
59 25
58 24
57 23
56 22
55 21
54 20
53 19
52 18
51 17
50 16
49 15
48 14
47 13
46 12
45 11
44 10
43 9
42 8
41 7
40 6
39 5
38 4
37 3
36 2
35 1
DIO38 DIO36
DIO34
DIO32
DIO30
DIO28
+5V
+5V
DGND DGND
DGND
DGND
DGND DGND DGND
DGND
DGND
DGND
DGND DGND
DGND
DGND
DGND
DGND
DGND
DGND DGND
DGND
DGND
DGND DGND
DGND
DGND
DGND
AI0+
AIGND0
AI1+
AI2+
AIGND2
AI3+
No Connect
AIGND4
No Connect No Connect
AIGND6
No Connect
AISENSE
AO0
AO1
AO2
AO3
No Connect
No Connect No Connect
No Connect
DIO15
DIO13
DIO11
DIO9
DIO7
DIO6
DIO5
DIO4 DIO3
DIO2
DIO1
DIO0
+5V
68 34
67 33
66 32
65 31
64 30
63 29
62 28
61 27
60 26
59 25
58 24
57 23
56 22
55 21
54 20
53 19
52 18
51 17
50 16
49 15
48 14
47 13
46 12
45 11
44 10
43 9
42 8
41 7
40 6
39 5
38 4
37 3
36 2
35 1
AI0–
AIGND1
AI1
AI2
AIGND3 AI3
No Connect
AIGND5
No Connect No Connect
AIGND7
No Connect
No Connect AOGND0 AOGND1
AOGND2
AOGND3
AOGND4
AOGND5 AOGND6
AOGND7
DIO14
DIO12
DIO10
DIO8
DGND DGND
DGND
DGND
DGND DGND
DGND
DGND
+5V
AI0+
AIGND0
AI1+
AI2+
AIGND2
AI3+
AI4+
AIGND4
AI5+ AI6+
AIGND6
AI7+
AISENSE
AO0
AO1
AO2
AO3
AO4
AO5 AO6
AO7
DIO15
DIO13
DIO11
DIO9
DIO7
DIO6
DIO5
DIO4 DIO3
DIO2
DIO1
DIO0
+5V
68 34
67 33
66 32
65 31
64 30
63 29
62 28
61 27
60 26
59 25
58 24
57 23
56 22
55 21
54 20
53 19
52 18
51 17
50 16
49 15
48 14
47 13
46 12
45 11
44 10
43 9
42 8
41 7
40 6
39 5
38 4
37 3
36 2
35 1
AI0–
AIGND1
AI1
AI2
AIGND3 AI3
AI4
AIGND5
AI5 AI6
AIGND7
AI7
No Connect AOGND0 AOGND1
AOGND2
AOGND3
AOGND4
AOGND5 AOGND6
AOGND7
DIO14
DIO12
DIO10
DIO8
DGND DGND
DGND
DGND
DGND DGND
DGND
DGND
+5V
NI 783xR DIO
Connector Pin Assignment
NI 7830R MIO
Connector Pin Assignment
NI 7831R/7833R MIO
Connector Pin Assignment

Figure B-2. NI 783xR I/O Connector Pin Assignments

To access the signals on the I/O connectors, you must connect a cable from the I/O connector to a signal accessory. Plug the small VHDCI connector end of the cable into the appropriate I/O connector and connect the other end of the cable to the appropriate signal accessory.
NI 783xR User Manual B-2 ni.com
Page 58
Appendix B Connecting I/O Signals

Table B-1. I/O Connector Signal Descriptions

Signal Name Reference Direction Description
+5V DGND Output +5 VDC Source—These pins supply 5 V from the computer
power supply using a self-resetting 1 A fuse. No more than 250 mA should be pulled from a single pin.
AI<0..7>+ AIGND Input Positive input for Analog Input channels 0 through 7.
AI<0..7>– AIGND Input Negative input for Analog Input channels 0 through 7.
AIGND Analog Input Ground—These pins are the reference point for
single-ended measurements in RSE configuration and the bias current return point for differential measurements. All three ground references—AIGND, AOGND, and DGND—are connected to each other on the NI 783xR.
AISENSE AIGND Input Analog Input Sense—This pin serves as the reference node
for AI <0..7> when the device is configured for NRSE mode.
AO<0..7> AOGND Output Analog Output channels 0 through 7. Each channel can
source or sink up to 2.5 mA.
AOGND Analog Output Ground—The analog output voltages
are referenced to this node. All three ground references—AIGND, AOGND, and DGND—are connected to each other on the NI 783xR.
DGND Digital Ground—These pins supply the reference for the
digital signals at the I/O connector and the 5 V supply. All three ground references—AIGND, AOGND, and DGND—are connected to each other on the NI 783xR.
DIO<0..15> Connector 0
DGND Input or
Output
Digital I/O signals.
.
DIO<0..39> Connector <1..2>
Caution Connections that exceed any of the maximum ratings of input or output signals
on the NI 783xR can damage the NI 783xR and the computer. Maximum input ratings for each signal are in the Protection column of Table B-2. NI is not liable for any damage resulting from such signal connections
© National Instruments Corporation B-3 NI 783xR User Manual
Page 59
Appendix B Connecting I/O Signals

Table B-2. NI 783xR I/O Signal Summary

Signal
Type and
Signal Name
+5V DO
AI<0..7>+ AI 10 GΩ in
AI<0..7>– AI 10 G in
AIGND AO
AISENSE AI 10 G in
AO<0. .7> AO 1.25 Short
AOGND AO
DGND DO
DIO<0..15> Connector 0
DIO<0..39> Connector <1..2>
Direction
DIO –0.5
Impedance
Input/
Output
parallel with
100 pF
parallel with
100 pF
parallel with
100 pF
Protection
(Volts)
On/Off
42/35 ±2nA
42/35 ±2nA
42/35 ±2nA
circuit to
ground
to +7.0
Source
(mA at V)
2.5 at 10 2.5 at –10 10 V/µs
5.0 at 2.4 5.0 at 0.4 12 ns
Sink
(mA at V)
Rise Time Bias
AI = Analog Input AO = Analog Output DIO = Digital Input/Output DO = Digital Output
Connecting to CompactRIO Extension I/O Chassis
You can use the CompactRIO R Series Expansion chassis and CompactRIO I/O modules with the NI 783xR. Refer to the CompactRIO R Series Expansion System Installation Instructions for information about connecting the chassis to the NI 783xR.
NI 783xR User Manual B-4 ni.com
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Appendix B Connecting I/O Signals
Connecting to 5B and SSR Signal Conditioning
NI provides cables that allow you to connect signals from the NI 783xR directly to 5B backplanes for analog signal conditioning and SSR backplanes for digital signal conditioning.
The NSC68-262650 cable connects the signals on the NI 783xR MIO connector directly to 5B and SSR backplanes. This cable has a 68-pin male VHDCI connector on one end that plugs into the NI 783xR MIO connector. The other end of this cable provides two 26-pin female headers plus one 50-pin female header.
One of the 26-pin headers contains all the NI 783xR analog input signals. You can plug this connector directly into a 5B backplane for analog input signal conditioning. The NI 783xR AI<0..n> correspond to the 5B backplane channels <0..n> in sequential order. Configure the AI channels to use the NRSE input mode when using 5B signal conditioning.
The other 26-pin header contains all the NI 783xR analog output signals. You can plug this connector directly into a 5B backplane for AO signal conditioning. The NI 783xR AO<0..n> correspond to the 5B backplane channels <0..n> in sequential order.
The 50-pin header contains the 16 DIO lines available on the NI 783xR MIO connector. You can plug this header directly into an SSR backplane for digital signal conditioning. DIO lines <0..15> correspond to the 5B backplane Slots <0..15> in sequential order.
The 5B connector pinouts are compatible with eight-channel 5B08 backplanes and 16-channel 5B01 backplanes. The NI 7830R can accept analog input from the first four channels of a 16-channel backplane. The NI 7831R/7833R can accept analog input from the first eight channels of a 16-channel backplane. The SSR connector pinout is compatible with eight-, 16-, 24-, and 32-channel SSR backplanes. You can connect to an SSR backplane containing a number of channels unequal to the 16 DIO lines available on the 50-pin header. In this case, you have access to only the channels that exist on both the SSR backplane and the NSC68-262650 cable 50-pin header.
Figure B-3 shows the connector pinouts when using the NSC68-262650 cable.
© National Instruments Corporation B-5 NI 783xR User Manual
Page 61
Appendix B Connecting I/O Signals
AO0
AOGND0
AO1 AO2
AOGND2
AO3 AO4
AOGND4
AO5 AO6
AOGND6
AO7
NC
AO 0–7 Connector
Pin Assignment
11 13 15 17 19 21 23 25
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
2
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50
NC
4
NC
6
NC
8
NC NC NC NC NC NC NC NC NC NC NC NC NC NC DGND DGND DGND DGND DGND DGND DGND DGND
1 3 5 7 9
NC NC NC NC NC NC NC
NC DIO15 DIO14 DIO13 DIO12
1 3 5 7 9
2 4 6
8 10 12 14 16 18 20 22 24 26
NC NC AOGND1 NC NC AOGND3 NC NC AOGND5 NC NC AOGND7 NC
AI0+
AIGND0
AI1+ AI2+
AIGND2
AI3+ AI4+
AIGND4
AI5+ AI6+
AIGND6
AI7+
AISENSE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
AI 0–7 Connector
Pin Assignment
AI0– AI1– AIGND1 AI2– AI3– AIGND3 AI4– AI5– AIGND5 AI6– AI7– AIGND7 NC
DIO11 DIO10
DIO9 DIO8 DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
+5V
DIO 0–15 Connector
Pin Assignment

Figure B-3. Connector Pinouts when Using NSC68-262650 Cable

The NSC68-5050 cable connects the signals on the NI 783xR DIO connectors directly to SSR backplanes for digital signal conditioning. This cable has a 68-pin male VHDCI connector on one end that plugs into the NI 783xR DIO connectors. The other end of this cable provides two 50-pin female headers.
You can plug each of these 50-pin headers directly into an 8-, 16-, 24-, or 32-channel SSR backplane for digital signal conditioning. One of the 50-pin headers contains DIO<0..23> from the NI 783xR DIO connector. These lines correspond to Slots <0..23> on an SSR backplane in sequential order. The other 50-pin header contains DIO<24..39> from the NI 783xR DIO connector. These lines correspond to Slots <0..15> on an SSR backplane in sequential order. You can connect to an SSR backplane containing a number of channels unequal to the number of lines on the
NI 783xR User Manual B-6 ni.com
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Appendix B Connecting I/O Signals
NSC68-5050 cable header. In this case, you have access only to the channels that exist on both the SSR backplane and the NSC68-5050 cable header you are using.
Figure B-4 shows the connector pinouts when using the NSC68-5050 cable.
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
2
1
4
3
6
5
8
7
10
9
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50
DIO23 DIO22 DIO21 DIO20 DIO19 DIO18 DIO17 DIO16 DIO15 DIO14 DIO13 DIO12 DIO11 DIO10
DIO9 DIO8 DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 DIO0
+5V
DIO 0–23 Connector
Pin Assignment
NC NC NC NC NC NC NC NC NC DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND
NC NC NC NC NC NC NC
NC DIO39 DIO38 DIO37 DIO36 DIO35 DIO34 DIO33 DIO32 DIO31 DIO30 DIO29 DIO28 DIO27 DIO26 DIO25 DIO24
+5V
DIO 24–39 Connector
Pin Assignment
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
2
1
4
3
6
5
8
7
10
9
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50
NC NC NC NC NC NC NC NC NC NC NC NC NC NC NC DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND

Figure B-4. Connector Pinouts when Using the NSC68-5050 Cable

© National Instruments Corporation B-7 NI 783xR User Manual
Page 63
Using the SCB-68 Shielded Connector Block
This appendix describes how to connect input and output signals to the NI 783xR with the SCB-68 shielded connector block.
The SCB-68 has 68 screw terminals for I/O signal connections. To use the SCB-68 with the NI 783xR, you must configure the SCB-68 as a general-purpose connector block. Refer to Figure C-1 for the general-purpose switch configuration.
S5 S4 S3
C
S1
S2

Figure C-1. General-Purpose Switch Configuration for the SCB-68 Terminal Block

After configuring the SCB-68 switches, you can connect the I/O signals to the SCB-68 screw terminals. Refer to Appendix B, Connecting I/O Signals, for the connector pin assignments for the NI 783xR. After connecting I/O signals to the SCB-68 screw terminals, you can connect the SCB-68 to the NI 783xR with the SH68-C68-S shielded cable.
© National Instruments Corporation C-1 NI 783xR User Manual
Page 64
Technical Support and Professional Services
Visit the following sections of the National Instruments Web site at
ni.com for technical support and professional services:
Support—Online technical support resources at
include the following:
Self-Help Resources—For answers and solutions, visit the
award-winning National Instruments Web site for software drivers and updates, a searchable KnowledgeBase, product manuals, step-by-step troubleshooting wizards, thousands of example programs, tutorials, application notes, instrument drivers, and so on.
Free Technical Support—All registered users receive free Basic
Service, which includes access to hundreds of Application Engineers worldwide in the NI Developer Exchange at
ni.com/exchange. National Instruments Application Engineers
make sure every question receives an answer.
For information about other technical support options in your area, visit
ni.com/contact.
Training and Certification—Visit
self-paced training, eLearning virtual classrooms, interactive CDs, and Certification program information. You also can register for instructor-led, hands-on courses at locations around the world.
System Integration—If you have time constraints, limited in-house
technical resources, or other project challenges, National Instruments Alliance Partner members can help. To learn more, call your local NI office or visit
Declaration of Conformity (DoC)—A DoC is our claim of
compliance with the Council of the European Communities using the manufacturer’s declaration of conformity. This system affords the user protection for electronic compatibility (EMC) and product safety. You can obtain the DoC for your product by visiting
ni.com/certification.
ni.com/services or contact your local office at
ni.com/alliance.
D
ni.com/support
ni.com/training for
© National Instruments Corporation D-1 NI 783xR User Manual
Page 65
Appendix D Technical Support and Professional Services
Calibration Certificate—If your product supports calibration,
you can obtain the calibration certificate for your product at
ni.com/calibration.
If you searched
ni.com and could not find the answers you need, contact
your local office or NI corporate headquarters. Phone numbers for our worldwide offices are listed at the front of this manual. You also can visit the Worldwide Offices section of
ni.com/niglobal to access the branch
office Web sites, which provide up-to-date contact information, support phone numbers, email addresses, and current events.
NI 783xR User Manual D-2 ni.com
Page 66

Glossary

Symbol Prefix Value
ppico10
nnano10
µ micro 10
m milli 10
k kilo 10
Mmega10
Ggiga10

Numbers/Symbols

° Degrees.
> Greater than.
–12
–9
–6
–3
3
6
9
Greater than or equal to.
< Less than.
Less than or equal to.
Negative of, or minus.
Ohms.
/Per.
% Percent.
± Plus or minus.
+ Positive of, or plus.
© National Instruments Corporation G-1 NI 783xR User Manual
Page 67
Glossary
+5V +5 VDC source signal.
Square root of.
A
A Amperes.
A/D Analog-to-digital.
AC Alternating current.
ADC Analog-to-digital converter—An electronic device, often an integrated
circuit, that converts an analog voltage to a digital number.
AI Analog input.
AI<i> Analog input channel signal.
AIGND Analog input ground signal.
AISENSE Analog input sense signal.
AO Analog output.
AO<i> Analog output channel signal.
AOGND Analog output ground signal.
ASIC Application-Specific Integrated Circuit—A proprietary semiconductor
component designed and manufactured to perform a set of specific functions.
B
bipolar A signal range that includes both positive and negative values (for example,
–5 to +5 V).
NI 783xR User Manual G-2 © National Instruments Corporation
Page 68
Glossary
C
CCelsius.
CalDAC Calibration DAC.
CH Channel—Pin or wire lead to which you apply or from which you read the
analog or digital signal. Analog signals can be single-ended or differential. For digital signals, you group channels to form ports. Ports usually consist of either four or eight digital channels.
cm Centimeter.
CMOS Complementary metal-oxide semiconductor.
CMRR Common-mode rejection ratio—A measure of an instrument’s ability to
reject interference from a common-mode signal, usually expressed in decibels (dB).
common-mode voltage Any voltage present at the instrumentation amplifier inputs with respect to
amplifier ground.
CompactPCI Refers to the core specification defined by the PCI Industrial Computer
Manufacturer’s Group (PICMG).
D
D/A Digital-to-analog.
DAC Digital-to-analog converter—An electronic device, often an integrated
circuit, that converts a digital number into a corresponding analog voltage or current.
DAQ Data acquisition—A system that uses the computer to collect, receive, and
generate electrical signals.
dB Decibel—The unit for expressing a logarithmic measure of the ratio of
two signal levels: dB = 20log10 V1/V2, for signals in volts.
DC Direct current.
DGND Digital ground signal.
DIFF Differential mode.
© National Instruments Corporation G-3 NI 783xR User Manual
Page 69
Glossary
DIO Digital input/output.
DIO<i> Digital input/output channel signal.
DMA Direct memory access—A method by which data can be transferred
to/from computer memory from/to a device or memory on the bus while the processor does something else. DMA is the fastest method of transferring data to/from computer memory.
DNL Differential nonlinearity—A measure in LSB of the worst-case deviation of
code widths from their ideal value of 1 LSB.
DO Digital output.
E
EEPROM Electrically erasable programmable read-only memory—ROM that can be
erased with an electrical signal and reprogrammed.
F
FPGA Field-Programmable Gate Array.
FPGA VI A configuration that is downloaded to the FPGA and that determines the
functionality of the hardware.
G
glitch An unwanted signal excursion of short duration that is usually unavoidable.
H
hHour.
HIL Hardware-in-the-loop.
Hz Hertz.
NI 783xR User Manual G-4 © National Instruments Corporation
Page 70
Glossary
I
I/O Input/output—The transfer of data to/from a computer system involving
communications channels, operator interface devices, and/or data acquisition and control interfaces.
INL Relative accuracy.
L
LabVIEW Laboratory Virtual Instrument Engineering Workbench. LabVIEW is a
graphical programming language that uses icons instead of lines of text to create programs.
LSB Least significant bit.
M
m Meter.
max Maximum.
MIMO Multiple input, multiple output.
min Minimum.
MIO Multifunction I/O.
monotonicity A characteristic of a DAC in which the analog output always increases as
the values of the digital code input to it increase.
mux Multiplexer—A switching device with multiple inputs that sequentially
connects each of its inputs to its output, typically at high speeds, in order to measure several signals with a single analog input channel.
© National Instruments Corporation G-5 NI 783xR User Manual
Page 71
Glossary
N
noise An undesirable electrical signal—Noise comes from external sources such
as the AC power line, motors, generators, transformers, fluorescent lights, CRT displays, computers, electrical storms, welders, radio transmitters, and internal sources such as semiconductors, resistors, and capacitors. Noise corrupts signals you are trying to send or receive.
NRSE Nonreferenced single-ended mode—All measurements are made with
respect to a common (NRSE) measurement system reference, but the voltage at this reference can vary with respect to the measurement system ground.
O
OUT Output pin—A counter output pin where the counter can generate various
TTL pulse waveforms.
P
PCI Peripheral Component Interconnect—A high-performance expansion bus
architecture originally developed by Intel to replace ISA and EISA. It is achieving widespread acceptance as a standard for PCs and work-stations. PCI offers a theoretical maximum transfer rate of 132 MB/s.
port (1) A communications connection on a computer or a remote controller.
(2) A digital port, consisting of four or eight lines of digital input and/or output.
ppm Parts per million.
pu Pull-up.
PWM Pulse-width modulation.
PXI PCI eXtensions for Instrumentation—An open specification that builds off
the CompactPCI specification by adding instrumentation-specific features.
NI 783xR User Manual G-6 © National Instruments Corporation
Page 72
Glossary
R
RAM Random-access memory—The generic term for the read/write memory that
is used in computers. RAM allows bits and bytes to be written to it as well as read from. Various types of RAM are DRAM, EDO RAM, SRAM, and VRAM.
resolution The smallest signal increment that can be detected by a measurement
system. Resolution can be expressed in bits, in proportions, or in percent of full scale. For example, a system has 12-bit resolution, one part in 4,096 resolution, and 0.0244% of full scale.
RIO Reconfigurable I/O.
rms Root mean square.
RSE Referenced single-ended mode—All measurements are made with respect
to a common reference measurement system or a ground. Also called a grounded measurement system.
RTSI Real-time system integration bus—The timing and triggering bus that
connects multiple devices directly. This allows for hardware synchronization across devices.
S
s Seconds.
S Samples.
S/s Samples per second—Used to express the rate at which a DAQ board
samples an analog signal.
signal conditioning The manipulation of signals to prepare them for digitizing.
slew rate The voltage rate of change as a function of time. The maximum slew rate
of an amplifier is often a key specification to its performance. Slew rate limitations are first seen as distortion at higher signal frequencies.
© National Instruments Corporation G-7 NI 783xR User Manual
Page 73
Glossary
T
THD Total harmonic distortion—The ratio of the total rms signal due to
harmonic distortion to the overall rms signal, in decibel or a percentage.
thermocouple A temperature sensor created by joining two dissimilar metals. The
junction produces a small voltage as a function of the temperature.
TTL Transistor-transistor logic.
two’s complement Given a number x expressed in base 2 with n digits to the left of the radix
point, the (base 2) number 2nx.
V
V Volts.
VDC Volts direct current.
VHDCI Very high density cabled interconnect.
VI Virtual instrument—Program in LabVIEW that models the appearance and
function of a physical instrument.
V
IH
V
IL
V
OH
V
OL
V
rms
Volts, input high.
Volts, input low.
Volts, output high.
Volts, output low.
Volts, root mean square.
W
waveform Multiple voltage readings taken at a specific sampling rate.
NI 783xR User Manual G-8 © National Instruments Corporation
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