National Instruments NI PCI-8254R - Manual (Page 12)

© National Instruments Corporation 2-1 NI PCI-8254R User Manual
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Digital I/O
The digital I/O functions on the NI 8254R are accessible through 2 TTL
inputs, 10 TTL outputs, 13 isolated inputs, and 4 isolated outputs.
You can use input signals as triggers, product selection ports, change
detectors, or to read quadrature encoders. Uses for output signals include
controlling camera reset and exposure, controlling strobe lighting,
outputting inspection results, or communicating with PLCs. You can also
define the functions of digital input and output signals.
For information about how to use LabVIEW to implement specific digital
I/O functions, refer to the examples at
<LabVIEW>\examples\IMAQ\
IMAQ IO.llb . For information about how to use C or Visual Basic to
implement specific digital I/O functions, refer to the examples at
<National Instruments>\NI-IMAQ IO\Examples\ .
RIO and LabVIEW FPGA
Behind the digital I/O of the NI 8254R is an FPGA which has been
preconfigured with the functionality required for most common machine
vision tasks. If the factory configured functionality does not fulfill your
requirements, the FPGA is user configurable with the LabVIEW FPGA
Module. RIO technology, found throughout the NI platform, includes
NI PCI and PXI R Series DAQ devices, NI CVS-1450 Series Compact
Vision Systems, the NI 8254R, the NI 8255R, and NI CompactRIO. RIO
allows you to develop custom FPGA logic on compact vision systems or
with the NI 8254R device to add triggering, pulse-width modulation
signals, or custom communications protocols to your machine vision
application.
Using National Instruments RIO hardware and the LabVIEW FPGA
Module, you can define your hardware without in-depth knowledge of
hardware design tools or hardware description languages (HDL). When the
signal requirements change, the LabVIEW code can be modified and
downloaded to the FPGA to change the I/O mix or type. This flexibility
allows you to reuse the same hardware and software at no extra expense.