Hi Yap,
I'm just posting the code I sent you in case other users come across this forum thread.
From my research I couldn't find a way to improve the resolution of the duty cycle returned from the pulse width measurements VI. Suggested using a counter channel to measure the pulse period and the pulse width and use those values to calculate the duty cycle. This example only works for TTL compatible signals.
Attached is some example code in LabVIEW version 7.1 to do this.
Sarah
Applications Engineer | National Instruments | UK & Ireland