Digital I/O Trigger Wiring

As noted above, the event notification on input lines is mono-directional. Inputs 0 to 7 can be used as a low-to-high trigger only, while inputs 8 to 15 can be used as a high-to-low trigger. In cases where trigger events are needed from both edges of a signal, the signal needs to be simultaneously wired to a low-to-high sensitive input pin and a high-to-low sensitive pin as shown in the above diagram. All 16 inputs are available for general purpose reading when not used for triggering events.

Connecting a Switch Input