I am trying to isolate control signals that are used to remotely operate a variable frequency drive. One is a 0-5V analog voltage signal that give the VFD its set point. I understand that optocouplers can be used to transmit digital signals as well as current across the optocoupler which may in some applications be leveraged to isolate an analog voltage signal if you set up the circuit correctly to convert and pass current rather than voltage. I was hoping for a detailed explanation for someone who is a novice in circuitry that could explain how to set up this circuit ideally with non specialized optocouplers, or if specialized optocouplers are required, how to evaluate a specific optocoupler for its appropriateness. (In my case specifically, there are 2 types of optocouplers available at my uni so would like to know how to select one rather than a specific recommendation).
Also, I know there may be other, simpler ways to achieve my purpose of signal isolation for my VFD control, but I am interested regardless in the answer to this question using optocouplers