Can a 4-20 mA (constant VDC) analog output on an industrial controller be used as an input on a solid state relay? I wasn’t sure how a device behaving as a variable current source might interact with a load such as the LED in an solid state relay that varies in its current draw. For example, what would happen if at a certain VDC, the controller output less mA than the LED drew at that voltage? Also, what are potential dangers of using this unconventional method?