Connecting Digital I/O Signals - DAQ DAQCard-1200 User Manual

Connecting Digital I/O Signals

Caution The DAQCard-1200 DIO lines are not pulled up or pulled down. If you are using
these lines as digital outputs, add 10 kΩ resistors to +5 V or DGND (depending on your
application) to the DIO line(s) you are using.
© National Instruments Corporation
Pins 13 through 37 of the front connector are DIO signal pins. DIO on the
DAQCard-1200 uses the 82C55A integrated circuit. The 82C55A is a
general-purpose peripheral interface containing 24 programmable I/O pins.
These pins represent the three 8-bit ports (PA, PB, and PC) of the 82C55A.
Pins 14 through 21 are connected to the digital lines PA<0..7> for DIO port
A. Pins 22 through 29 are connected to the digital lines PB<0..7> for DIO
port B. Pins 30 through 37 are connected to the digital lines PC<0..7> for
DIO port C. Pin 13, DGND, is the digital ground pin for all three DIO ports.
Refer to Appendix A, Specifications, for signal voltage and current
specifications.
3-15
Chapter 3 Connecting the Signals
DAQCard-1200 User Manual