The FP-DI-330 Universal Discrete input modules will accept AC or DV signals from 5 to 250 V. The threshold level for AC signals depends on the frequency of the signal. For sinusoidal signals with a frequency of 50 or 60 Hz, a signal of at least 15 Vrms results in a constant ON state. For signals of 1 KHz and higher, a signal of at least 3 Vrms results in a constant ON state. At any frequency, a constant OFF state is guaranteed when the peak voltage is less than 1 V. For AC signals in the transition region between the 1 V guaranteed OFF voltage and the guaranteed ON voltages described above, the FP-DI-330 may register the state as either ON, OFF, or as a signal alternating between ON and OFF.
Alternatively, you can use a FP-AI-100 module which is an Analog Input module desi
gned to handle signals as large as +/- 36 Volts, and then threshold it yourself. The FP-AI-100 has an input signal bandwith of 170 Hz.
LabVIEW Champion, CLA, CPI
