Figure 3.4 Ttl-Level Di/O Connection; Figure 3.5 Open/Short Connection - Advantech PCI-1730 User Manual

TTL-level Digital Input/Output
The PCI-1730 has 16 TTL-level digital inputs and 16 TTL-level digital
outputs. The following figure shows connections to exchange digital
signals with other TTL devices:
If you want to receive an OPEN/SHORT signal from a switch or relay, add a pull-up
resistor to ensure that the input is held at a high level when the contacts are open.
See the figure below:
PCI-1730/1733/1734 User Manual
PCI-1730
DO
DI
GND

Figure 3.4 TTL-level DI/O Connection

PCI-1730
DI
GND

Figure 3.5 Open/Short Connection

24
TTL device
+5V
4.7K
Switch