We are using a variable frequency drive that has a frequency output relative to output current of the drive. The input value is very flacky and unstable. We contacted the manufacutrer and they realized they had a problem. They suggest an RC circuit. Here is what they suggested.
For a 0-5VDC output, R1 = 698 ohms
R2 = 0.23 x Z, where Z is the input impedance of the digital instrument or PLC
C1 = 0.02 ? R2, select the next larger standard value of capacitance.
I have an entire page from them, but didn't want to bore you. Please advise.
Thanks again,