A wire feeder including a motor driving a set of feed rolls to force a welding wire from a spool through a welding torch to a welding operation. The wire feeder has an input lead to be connected to the output lead of one of a plurality of remotely located power sources, each having a signal receiver for receiving transmitted signal with a code unique to one of the power sources. The receiver having an output for controlling a parameter or condition of the one power source in accordance with a received signal with the unique code. A transmitter on each of said plurality of power sources for transmitting on its output lead a coded signal specific to the power source. A signal receiver on said wire feeder to receive a unique code from the specific power source actually connected to the wire feeder and a circuit on the wire feeder for transmitting command signals from the wire feeder, which command signals each have the unique code specific to the power source connected to said wire feeder.