Hello,
I would suggest running a Counter Input task for Digital Frequency. This would allow your signal to control the timing, since the encoder input would be wired into the gate and the internal timebase would route to the source. The original (unmodified) example is located in the Example Finder Browse tab under the following folders … <Hardware Input and Output> <DAQmx> <Counter Measurements> <Digital Frequency>.
Please note that there is also an example for measuring the angular position for an encoder. These example are located in the <Position> folder inside of <Counter Measurements> . This would require an addition counter, since it is also a Counter Input task. The 6251 has two counters, so you could measure both at the same time if needed.
Samantha
National Instruments
Applications Engineer
