I am trying to measure the frequency of a signal using the one counter method and a 6025E card. I have connected the output of a LM319(high speed dual comparator) to pin 24 (DGND) and pin 48 (0-gate). Although a led connected to the output lights up in pulses the labVIEW counter cannot measure the frequency. I believe that this indicates that I have a TTL output but it is not clean enough for the counter. Is that right? I believe the rise time for LM319 is 80 ns while the counter detects only TTL with rise time less than 50 ns. Is that right? Someone in the forum suggested that I connect a 74F14 Hex inverter schmitt trigger between the LM319 and the Daq. The 74F14 has a rise time of 9 ns. Would that solve my problem?
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