©
National Instruments Corporation
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6527 Register-Level Programmer Manual
1
Getting to Know Your 6527
Your 6527 device is a 48-bit, parallel, isolated digital I/O interface; the PCI-6527 for PCI bus
computers, and the PXI-6527 for PXI or CompactPCI chassis. The 6527 devices offer
48 channels of isolated digital data acquisition. Twenty-four of the channels are optocoupler
inputs and 24 are solid-state relay outputs. You can sense digital levels up to 28 VDC and
switch currents of up to 120 mA. Your device can perform digital filtering, which eliminates
glitches on input lines and change notification. This change notification can then generate
interrupts on rising or falling edges on input lines to notify you of changing data.
For more information regarding the functions, installation, connections, and safe use of
the 6527, refer to the
6527 User Manual
.
Caution
Using your 6527 device in a way inconsistent with the directions in the
6527 User
Manual
can lead to equipment damage or injury. National Instruments is
not
liable for
damage or injuries resulting from incorrect use.
Using Your 6527
The 6527 circuitry can be divided into the following functional groups:
•
PCI interface
•
General operation registers
•
Digital filtering registers
•
Change notification registers
PCI Interface
The 6527 uses the PCI MITE Application-Specific Integrated Circuit (ASIC) to communicate
with the PCI or PXI bus. National Instruments designed this ASIC specifically for data
acquisition. Before register-level programming the 6527 device, you must initialize the
PCI interface as described in Chapter 3,
