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National Instruments Corporation
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Introduction
This chapter describes the NI 781
x
R, the concept of the Reconfigurable I/O
(RIO) device, optional software and equipment for using the NI 781
x
R, and
safety information about the NI 781
x
R.
About the Reconfigurable I/O Devices
The NI 781
x
R devices are R Series RIO devices with 160 digital I/O (DIO)
lines and four DIO connectors.
•
The NI 7811R has a one million gate Field-Programmable Gate Array
(FPGA).
•
The NI 7813R has a three million gate FPGA.
A user-reconfigurable FPGA controls the digital I/O lines on the NI 781
x
R.
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 have LabVIEW but not the FPGA Module, you
cannot create new FPGA VIs, but you can create VIs that run on Windows
or on a LabVIEW Real-Time (RT) target to control existing FPGA VIs.
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.
The NI 781
x
R uses the Real-Time System Integration (RTSI) bus to easily
synchronize several measurement functions to a common trigger or timing
event. The NI 781
x
R accesses the RTSI bus through the PXI trigger lines
implemented on the PXI backplane. The RTSI bus can route timing and
trigger signals between as many as seven PXI devices in your system.
