Hello Tizianos,
If you create a GPI action. With the trigger type set to channel. The trigger value is used to specify the GPI pin you are using.
Then you can set the trigger flank. This is used to detect a high or low signal.
Use the flank Change when you want the action to trigger on both a high and a low signal.
Use Up to trigger on a high signal.
Use Down to trigger on a low signal.
If you have to do something when there is a high signal. Create an action with the trigger flank set to Up. If you then also have to do something diferent when there is a low signal. You can create a second action with the trigger flank set to Down.
Best regards,
Guido