BioSemi.nl

Posted: **Wed Jul 29, 2009 7:20 pm**

We would like to use Pin01 (Trigger input 1) in the USB interface to acquire a sync signal from an external electronic circuit. We have found a voltage difference of 3 V between pin01 and pin37 (ground). Is that difference ok? Shouldn't that difference be zero when unplugged?
Thanks!

Posted: **Thu Jul 30, 2009 2:34 pm**

It's normal, the measured 3V is due to the internal pull-up resistors (10 kOhm to 5V). The inputs are pulled high when left unconnected.

Best regards, Coen (BioSemi)

BioSemi.nl

voltage difference between pin1 and pin37

voltage difference between pin1 and pin37