Measuring Two-Edge Separation

You can use the counters on your measurement device to measure two-edge separation. Two-edge separation is the time between the rising or falling edge of one digital signal (Signal A in the following figure) and the rising or falling edge of another digital signal (Signal B in figure).

The formula for two-edge separation is as follows:

Two-Edge Separation (in seconds) = Count / Counter Timebase Rate (in hertz)

where Count is the number of counter timebase ticks between the specified edge of the first signal and the specified edge of the second signal.

The Counter Timebase Rate is a known frequency for making frequency and time measurements. To configure a measurement, specify the expected range of the input signal. Based on this range, NI-DAQmx automatically selects the internal timebase that provides the highest resolution for your measurement and uses that timebase as the counter timebase.