how to acquire open collector output data ,

[rakeshkumar68]

 the output data that comes from a single wire from the instrument without the ground signal from the instrument , ie , the open collector output data. which is the cheapest and the best NI hardware to acquire open collector output data ?

[crossrulz · Accepted solution]

cross posted on LAVA:http://lavag.org/topic/16327-acquisition-of-open-collector-output-data/

As said in the LAVA thread, there has to be a ground reference somewhere.  Now the question is are you trying to measure the output voltage or the state of the output?