Hello,

I need to drive an EDC control pump which needs 16-90 mA command signal to drive Feeder hyd. motor at variable speed. There is a handheld radio remote transmitter with a potentiometer to change speed of the feeder drive. The S7-200 smart PLC takes this input through a radio modem and needs to drive the pump accordingly. But if I consider AO module it can give 4-20 mA output only. So my question is how can I get 16-90 mA output from the PLC?

Please help me.

Hello,

in time of Internet I really don't understand why you don't work with it, especially with Google where you can find probably all what you need. My first attempt for search something:

http://www.axiomatic.com/signal-converter/4-20-ma-to-current-converter/

Hope it will help you.