I do not believe an FP-QUAD-510 can be used to measure PWM. The FP-QUAD-510 requires two inputs A and B and increments or decrements the position count by the changing of A and B with respect to each other (e.g. AB, !AB,!A!B, A!B). Whereas the FP-QUAD-510 does also provide a velocity reading (counts/usec), wiring a single signal to A or B and will simply result in the count incrementing by 1 then decrementing by 1 then incrementing by 1 etc... This will not yield accurate results on the velocity reading.
Depending upon the period of your pulse width signal, you may want to consider using a FP-CTR-500 or FP-CTR-502 module. The counter modules can use internal clocks to allow you to measure the on-period of the signal. If you know the signal is always the exact
same period, by measuring the on-period portion of the total period you can determine the duty cycle. If the period of the signal will vary, then you can still use a counter module, but will need to use multiple channels (one for the on-period and one for the off-period) and an external inverter on the signal (you would feed the signal into one count channel and the inverted signal into a second count channel).
Regards,
Aaron
LabVIEW Champion, CLA, CPI
