National Instruments NI PXI-7831R User manual

©2003 National Instruments Corp. All rights reserved.
LabVIEW™, National Instruments™, NI™, ni.com™, and NI-VISA™ are trademarks of National Instruments Corporation.
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covering National Instruments products, refer to the appropriate location: Help»Patents in your software, the
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April 2003
323256A-01
Where to Start with the NI PXI-7831R
Thank you for purchasing a National Instruments PXI-7831R. This
document explains how to set up the hardware system and use the
NI PXI-7831R. This reconfigurable I/O (RIO) device has 96 digital I/O
(DIO) lines, eight independent, 16-bit analog output (AO) channels, and
eight independent, 16-bit analog input (AI) channels.
A user-reconfigurable field-programmable gate array (FPGA) controls the
digital and analog I/O on the NI PXI-7831R. The FPGA on the RIO device
allows you to define the functionality and timing of the device, whereas
traditional multifunction I/O (MIO) devices have a fixed functionality
provided by an application-specific integrated circuit (ASIC). You can
change the functionality of the FPGA on the RIO device by using
LabVIEW, a graphical programming environment, and the LabVIEW
FPGA module to create and download a custom virtual instrument (VI) to
the FPGA. You can reconfigure the RIO device with a new VI at any time.
Using LabVIEW, you can graphically design the timing and functionality
of the RIO device without having to learn the low-level programming
language or hardware description language (HDL) that is traditionally used
for FPGA design.
Note If you have LabVIEW and not the LabVIEW FPGA module, you cannot create new
FPGA VIs. You can only create VIs that run in LabVIEW to control existing FPGA VIs.
Some applications require tasks such as real-time, floating-point
processing or data logging while performing I/O and logic on the RIO
device. You can use the LabVIEW Real-Time Module to perform these
additional applications while also communicating with and controlling the
RIO device.
The RIO device contains flash memory to store VIs for instant loading of
the FPGA when the system is powered on.
ni.com

Where to Start with the NI PXI-7831R 2 ni.com
What You Need to Get Started
This section contains two lists that detail what you need to get started using
the NI PXI-7831R with the LabVIEW Real-Time Module or with
Windows 2000/XP.
Getting Started with Windows 2000/XP
To set up and use the NI PXI-7831R with Windows 2000/XP, you need the
following items:
❑NI PXI-7831R
❑The following software packages:
– LabVIEW version 7.0 or later
– NI Device Drivers CD
– LabVIEW FPGA Module version 7.0 or later (required to develop
custom FPGA VIs for the RIO device)
❑PXI/CompactPCI chassis and a PXI/CompactPCI embedded
controller, running Windows 2000/XP (or any computer running
Windows 2000/XP and a MXI-3 link to a PXI/CompactPCI chassis)
❑At least one cable and terminal block for connecting signals to the
NI PXI-7831R
❑The following documents are included on the NI Device Drivers CD
and are also available at ni.com/manuals (optional):
– LabVIEW FPGA Module Release Notes
–LabVIEW FPGA Module User Manual
– NI PXI-7831R User Manual
❑The LabVIEW Help,which is available by selecting Help»VI,
Function, & How-To Help from LabVIEW
Getting Started with the LabVIEW Real-Time Module
To set up and use the NI PXI-7831R with the LabVIEW FPGA Module and
the LabVIEW Real-Time Module, you need the following items:
❑NI PXI-7831R
❑The following software packages:
– LabVIEW version 7.0 or later
– NI Device Drivers CD

©National Instruments Corporation 3 Where to Start with the NI PXI-7831R
– LabVIEW FPGA Module version 7.0 or later (required only if you
are developing custom FPGA VIs for the RIO device)
– LabVIEW Real-Time Module version 7.0 or later
❑PXI/CompactPCI chassis and real-time PXI controller
❑One of the following host computers, depending upon your
application, running Windows 2000/XP:
–PC
– Laptop computer
– PXI/CompactPCI embedded controller
❑At least one cable and terminal block for connecting signals to the
NI PXI-7831R
❑Category 5 (Cat-5) crossover cable (if the real-time PXI system is not
configured on a network); you need a regular network cable if you are
configured on a network
❑The following documents are included on the NI Device Drivers CD
and are also available at ni.com/manuals (optional):
– LabVIEW FPGA Module Release Notes
– LabVIEW FPGA Module User Manual
–LabVIEW Real-Time Module User Manual
– NI PXI-7831R User Manual
❑The LabVIEW Help, which is available by selecting Help»VI,
Function, & How-To Help from LabVIEW
Installing the Software
The following software installation instructions describe how to install the
NI Device Drivers software for use without the LabVIEW FPGA Module.
If you are using the FPGA Module, refer to the LabVIEW FPGA Module
Release Notes document for software installation instructions.
Note NI recommends that you install LabVIEW 7.0 or later before installing the
NI Device Drivers software. For LabVIEW installation instructions, refer to the LabVIEW
Release Notes document.

Where to Start with the NI PXI-7831R 4 ni.com
Complete the following steps to install the necessary components from the
NI Device Drivers CD.
1. Log onto the computer as an administrator or as a user with
administrative privileges.
2. Insert the NI Device Drivers CD (for LabVIEW 7.0 or later) into the
CD drive.
3. Run setup.exe from the NI Device Drivers CD.
4. Follow the instructions that appear on the screen until you reach the
Feature Tree window.
5. In the Feature Tree window, you can select the components to install.
You must install all the components for NI-VISA, NI-RIO, and
NI Measurement & Automation Explorer. You also can install other
components.
6. Complete the driver installation and remove the NI Device Drivers CD.
7. You must shut down your computer before installing any hardware.
Unpacking
The RIO device is shipped in an antistatic package to prevent electrostatic
damage to the device. Electrostatic discharge (ESD) can damage several
components on the device.
Caution Never touch the exposed pins of connectors.
To avoid such damage when handling the devices, take the following
precautions:
• Ground yourself using a grounding strap or by holding a grounded
object.
• Touch the antistatic package to a metal part of the computer chassis
before removing the devices from the package.
Remove the devices from the package and inspect the devices for loose
components or any other sign of damage. Notify NI if the devices appear
damaged in any way. Do not install damaged devices into the computer.
Store the NI PXI-7831R in the antistatic envelope when not in use.

©National Instruments Corporation 5 Where to Start with the NI PXI-7831R
Installing the Hardware
You can install the NI PXI-7831R in any available PXI slot in the
PXI/CompactPCI chassis.
The following are general installation instructions, so consult the computer
user manual or technical reference manual for specific instructions and
warnings.
Note You must install the software before installing the hardware. For software
installation instructions, refer to the Installing the Software section.
1. Power off and unplug the PXI/CompactPCI chassis.
2. Choose an unused PXI/CompactPCI peripheral slot.
3. Make sure there are no lighted LEDs on the chassis. If any are lit, wait
until they go out before continuing the installation.
4. Remove the filler panel for the peripheral slot that you chose.
5. Ground yourself using a grounding strap or by holding a grounded
object. Follow the electrostatic discharge protection precautions
described in the Unpacking section.
6. Insert the NI PXI-7831R into the slot. Use the injector/ejector handle
to fully inject the NI PXI-7831R into place.
7. Screw the front panel of the NI PXI-7831R to the front panel mounting
rails of the PXI/CompactPCI chassis.
8. Visually verify the installation by making sure the NI PXI-7831R is
not touching other devices or components and is fully inserted into
the slot.
9. Plug in and power on the PXI/CompactPCI chassis.
The NI PXI-7831R is now installed.

Where to Start with the NI PXI-7831R 6 ni.com
Connecting Signals
The NI PXI-7831R has two DIO connectors with 40 DIO lines per DIO
connector, and one MIO connector with eight AI lines, eight AO lines, and
16 DIO lines.
Figure 1 shows the I/O connector locations for the NI PXI-7831R. The I/O
connectors are numbered starting at zero. The text in parentheses indicates
whether each I/O connector is an MIO connector or a DIO connector.
Figure 1. NI PXI-7831R Connector Locations
NI PXI-7831R
CONNECTOR 0 (MIO) CONNECTOR 1 (DIO)
CONNECTOR 2 (DIO)
Reconfigurable I/O

©National Instruments Corporation 7 Where to Start with the NI PXI-7831R
Figure 2 shows the I/O connector pin assignments for the I/O connectors
on the NI PXI-7831R. The DIO connector pin assignment applies to
connectors <1..2> on the NI PXI-7831R. The MIO connector pin
assignment applies to connector 0 on the NI PXI-7831R.
Figure 2. NI PXI-7831R I/O Connector Pin Assignments
Connecting I/O Signals
To access the signals on the I/O connectors, you must use at least one cable
and one signal accessory. If you are connecting to a terminal block such as
an SCB-68, you should use the SH68-C68-S cable. Plug the small VHDCI
connector end of the SH68-C68-S shielded cable into the appropriate
I/O connector on the NI PXI-7831R, and connect the other end of the
SH68-C68-S cable into the terminal block.
DIO Connector Pin Assignment Multifunction I/O Connector Pin
Assignment
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
+5V
+5V
DIO28
DIO30
DIO32
DIO34
DIO36
DIO38
DIO0
DIO2
DIO3
DIO5
DIO6
DIO7
DIO8
DIO1
DIO4
DIO9
DIO10
DIO11
DIO12
DIO13
DIO14
DIO15
DIO16
DIO17
DIO18
DIO19
DIO20
DIO21
DIO22
DIO23
DIO24
DIO25
DIO26
DIO27
DIO29
DIO31
DIO33
DIO35
DIO37
DIO39
135
236
337
438
539
640
741
842
943
10 44
11 45
12 46
13 47
14 48
15 49
16 50
17 51
18 52
19 53
20 54
21 55
22 56
23 57
24 58
25 59
26 60
27 61
28 62
29 63
30 64
31 65
32 66
33 67
34 68
+5V
DGND
DGND
DGND
DGND
DGND
DGND
DGND
DGND
DIO8
DIO10
DIO12
DIO14
AOGND7
AOGND6
AOGND5
AOGND4
AOGND3
AOGND2
AOGND1
AOGND0
No Connect
AI7–
AIGND7
AI6–
AI5–
AIGND5
AI4–
AI3–
AIGND3
AI2–
AI1–
AIGND1
AI0–
+5V
DIO1
DIO2
DIO4
DIO5
DIO6
DIO7
DIO0
DIO3
DIO9
DIO11
DIO13
DIO15
AO7
AO6
AO5
AO4
AO3
AO2
AO1
AO0
AISENSE
AI7+
AIGND6
AI6+
AI5+
AIGND4
AI4+
AI3+
AIGND2
AI2+
AI1+
AIGND0
AI0+
135
236
337
438
539
640
741
842
943
10 44
11 45
12 46
13 47
14 48
15 49
16 50
17 51
18 52
19 53
20 54
21 55
22 56
23 57
24 58
25 59
26 60
27 61
28 62
29 63
30 64
31 65
32 66
33 67
34 68

Where to Start with the NI PXI-7831R 8 ni.com
NI also provides cables for connecting the NI PXI-7831R directly to
5B and SSR analog and digital signal conditioning backplanes. The
NSC68-262650 plugs directly into the MIO connector on the PXI-7831R
and routes the signals to connectors that can be attached directly to 5B
backplanes for the analog signals and SSR backplanes for the digital
signals. The NSC68-5050 plugs directly into the DIO connectors on the
PXI-7831R and routes the signals to connectors that can be attached
directly to SSR backplanes.
Refer to the NI PXI-7831R User Manual for more information on
connecting I/O signals.
Caution Connections that exceed any of the maximum ratings of input or output signals
on the NI PXI-7831R can damage the NI PXI-7831R and the computer. Refer to the
NI PXI-7831R User Manual for the maximum input ratings for each signal. NI is not liable
for any damage resulting from such signal connections.
Getting Started Example
The following instructions guide you through running a simple example on
the PXI-7831R. Running this example confirms that you have installed
your software and hardware correctly, and it provides a brief introduction
to using LabVIEW to program the PXI-7831R. This example uses the
default FPGA VI, which is installed along with the NI-RIO software, and
which is also programmed into the flash memory on the PXI-7831R before
the device is shipped from the factory.
Note The following example can be run by all users, even if you are not using the FPGA
Module. However, if you are using the FPGA Module, you might wish to consult the
LabVIEW FPGA Module Release Notes for more information on getting started with the
FPGA Module.
Complete the following steps to open and run the example program.
1. Launch LabVIEW.
2. (Real-Time Module users only) Select the networked Real-Time PXI
system from the Execution Target list in the LabVIEW dialog box to
target LabVIEW to the Real-Time system containing the PXI-7831R.
3. Click the Open arrow and select Examples from the pull-down menu
in the LabVIEW dialog box. The Example Finder window appears.
4. Select Directory Structure on the Browse tab to browse the examples
by directory structure.

©National Instruments Corporation 9 Where to Start with the NI PXI-7831R
5. Navigate to LabVIEW 7.0\examples\FPGA\Applets
\Default 7831\ in the listbox. Notice that a brief description of the
example appears in the Example description field of the Example
Finder dialog box.
6. Double-click 1 RIO Board (Host).vi in the listbox to launch the
1 RIO Board (Host) VI example.
7. Click the Run button.
8. If you are running a Real-Time system, a Downloading dialog box
appears to display the progress of the example VI as it downloads to
the Real-Time controller.
Some users might see a Downloading dialog box briefly appear to
display the progress of the FPGA VI as it downloads to the FPGA on
the NI PXI-7831R. This dialog box only appears if the FPGA VI is not
already downloaded to the FPGA.
9. The example should now be running and returning data from the
PXI-7831R. The example is acquiring data from AI channel 1 and
displaying that data on the indicator labeled AI 1. The data is displayed
as a signed 16-bit number that varies from –32768 to 32767 as the
voltage on AI channel 1 varies from –10.0 V to +10.0 V. If you have a
signal source available, connect it to AI channel 1 (connect AI1+ to the
signal, and AI1– to ground) and confirm that the data returned
corresponds to the voltage input. If you do not have a signal source
available, connect AI1+ and AI1– both to ground and confirm that the
number returned by the AI 1 indicator is close to 0.
10. The Loop Period control determines the analog input sampling rate.
This period is specified in cycles of the PXI-7831R onboard 40 MHz
oscillator. So, specifying a Loop Period of 40,000,000 results in the
analog input being sampled once every second. Vary the Loop Period
and watch how it affects the update rate of the AI 1 indicator. If you set
the Loop Period too low, the computer cannot read data from the AI
channel as fast as it is sampled. In this case, the Overrun indicator
lights up indicating that you are trying to run the example too fast.
11. Click the STOP button to stop the VI. If you encountered any
problems running the VI, refer back to the software and hardware
installation instructions in this document and verify that everything is
installed correctly.
12. Select Window»Show Block Diagram from the 1 RIO Board (Host)
VI toolbar to view the block diagram. This example actually consists
of two separate VIs—the 1 RIO Board (Host) VI, which runs on the
Windows or LabVIEW Real-Time machine, and a second VI, Default
7831R (FPGA) VI, which runs on the PXI-7831R FPGA. As you look
at the 1 RIO Board (Host) VI block diagram, the left-most terminal on
the block diagram is an Open FPGA VI Reference function that
downloads the Default 7831R (FPGA) VI to the FPGA on the

Where to Start with the NI PXI-7831R 10 ni.com
PXI-7831R. A reference to this VI running on the FPGA is passed to
the subsequent nodes on the block diagram. These nodes can interact
with the VI running on the FPGA by reading and writing its indicators
and controls to control the execution of the FPGA VI. After the While
Loop on the 1 RIO Board (Host) VI block diagram finishes execution,
the Close FPGA VI Reference function stops the execution of the VI
on the FPGA. Refer to the context help for the 1 RIO Board (Host) VI
for more information about the operation of this VI.
13. The Default 7831R (FPGA) VI that runs on the PXI-7831R FPGA
provides much more functionality than the 1 RIO Board (Host) VI
actually uses. The Default 7831R (FPGA) VI provides a timed loop
synchronizing all of the I/O available on the PXI-7831R (8 AI, 8 AO,
and 96 DIO). The Default 7831R (FPGA) VI offers a variety of
different timing modes that allow it to run off of its own internal loop
timer, or to synchronize its operation with other devices in the system.
To view the Default 7831R (FPGA) VI, double-click the Open FPGA
VI Reference function on the 1 RIO Board (Host) VI block diagram
using the selection tool. This opens the front panel for the Default
7831R (FPGA) VI. Refer to the context help for the Default 7831R
(FPGA) VI for more information about this VI. You can also look at
the block diagram code to see how this VI operates.
14. Close the 1 RIO Board (Host) VI and the Default 7831R (FPGA) VI,
and exit LabVIEW when you are done. For more information using
FPGA VIs like the Default 7831R (FPGA) VI, refer to the LabVIEW
FPGA Module User Manual.
Where To Go From Here
Refer to the following documentation for information about the
LabVIEW FPGA Module, RIO hardware, and VIs needed for your
application.
•LabVIEW FPGA Module Release Notes—This document describes the
software installation and other known software issues.
•LabVIEW FPGA Module User Manual—This manual describes the
LabVIEW FPGA Module software and techniques for building
applications in LabVIEW with the FPGA Module. Even if you do not
have the FPGA module installed, NI recommends that you read
Chapter 4, Communicating with FPGA VIs.
•NI PXI-7831R User Manual—This manual describes the electrical and
mechanical aspects of the NI PXI-7831R device and contains
information concerning its operation and programming.
•LabVIEW Help—This help describes the VIs and function reference
information.