Allen Bradley 4-20 mA input signal
Allen Bradley 4-20 mA input signal
(OP)
Is it possible to set up my PID in RS Logix 500 for a 4-20 mA input signal. I've done it a couple of times just using thermocouple inputs but know have a 4-20 mA Omega Infrared Thermometer/Transmitter. I'll appreciate any help.





RE: Allen Bradley 4-20 mA input signal
The resistor size should generate enough voltage a 20 mA to give you reasonable input range, but should also be kept as small as practical to reduce burden on the 4-20 mA transmitter. A 500 ohm resistor will 10V out at 20 mA and will generally work if you don't have too many other devices in series with the resistor. A 250 ohom resistor will provide 5 volts and this is generally adequate for most controllers.
RE: Allen Bradley 4-20 mA input signal