ADLINK PXI-2006 - Manual (Page 61)

Operation Theory 51
Figure 4-21: Stop mode II
Figure 4-22: Stop mode III
4.3 Digital I/O
The DAQ/PXI-20XX contains 24-lines of general-purpose digital I/
O (GPIO), which is provided through a 82C55A chip.
The 24-line GPIO are separated into three ports: Port A, Port B
and Port C. High nibble (bit[7…4]), and low nibble (bit[3…0]) of
each port can be indi-vidually programmed to be either inputs or
outputs. Upon system startup or reset, all the GPIO pins are reset
to high impedance inputs.
DAQ/PXI-2010 also provides 2 digital inputs per channel (SDI
from J5), which are sampled simultaneously with an analog signal