Hi,

Need some advise as I am having a pump with automatic stroke control by analog 4-20ma

There is input signal and feedback to Scada.

What i experienced,issue.

There is unknown interference that drift the actuator forward and backward.

We measured the input signal using milliam multimeter in series. It is constant in input.

Another issue when the VFD motor off, the stroke signal is deifting by itself. Not sure if there is possible intereference or rootcause that can be narrow down in the case of troubleshooting analog signal. Small Bio