Typical Digital I/O Wiring; Figure 4-4 Typical Non-Ttl Digital Input - Keithley PIO-32 User Manual

Typical Digital I/O Wiring

This section provides a typical non-TTL digital input wiring example for
the PIO-32IN board and a typical digital output control wiring example
for the PIO-32OUT board.
In the digital input example shown in Figure 4-4, the PIO-32IN board
monitors the presence of non-TTL signals. If no signal is present, the
input value is 0; if a non-TTL signal is present, the input value is 1. The
polarity matters for a digital input.
push button
+
(+)
Positive
R
PIO-32IN
LOAD
28V
Negative (-)
–
Figure 4-4. Typical Non-TTL Digital Input Wiring Example
4-5