GPIO Tolerance

What are the tolerances for input voltages for the signal pin of the GPIOs? In other words, at what point does the GPIO switch from reporting true (high) to false (low)? Does the signal pin have to be taken to 0 volts (i.e directly connected to ground) or is there some point where a low enough voltage will be considered low (and thus report false)?

if you are useing java you can print the output of it to the drive station, then through testing it you can get a ball park estement

From the datasheet for the DIO module at National Instruments

The module can take inputs with a voltage of –0.25 to 5.25 V

When the voltage exceeds 2.2 V, it is ‘high’
High, VIH 2.2 V min

When the voltage falls below 0.8 V, it is a ‘low’
Low, VIL 0.8 V max

Anything in-between is no-mans lands.

Exactly what we needed to know. Thanks!