I want to get a solution of controlling (ON/OFF) of A/C Split air conditioner. The AC is located in to an an maned communication station, and some times there is a power shut down of the main AC. Therefore the A/C required a physical contact to press the remote control of the A/C split Unit to start up. We are using digital microwave network linking our stations and we are using TDM Nokia multiplexing to drop channels at different station. The channel is a four fire circuit (4 wire + E and M signalling). Can any one give an idea on solving a such problem by introducing a circuit which can be representing the controlling of the Spit Air conditioner.