I am measuring the number of edges (per second)of a TTL signal to calculate the RPM of 2 gear drives. I get a random error due to software timing. I cannot use hardware timing as my PCI6014 card has just 2 counters. I have tried all other methods(period,pulse mesurement)using counters.
I have now connected my TTL signal to my AI channel0 and I am scaning it 10000 scans/ sec. I am then passing this waveform to single tone extraction vi to find out the frequency of my input TTL signal. But I get a totally different reading as my frequency. I get some frequency value even when my shaft does not rotate.I also tried the period,duty cycle using another VI available in waveform analysis palatte.
I eliminated all noise in the input signal by representin
g my input signal as an integer. So my input signal would be either 0 or 5V.
Is this the right approach? Or am I messing up.Please suggest the best way to measure frequency of a TTL pulse without using a counter.
