I have an Aqualink PDA-P8 control system which has one four-pin terminal block for RS485 communications. I presently have an ePump and the wireless transciever connected to the terminal block. The installation manual for the Aqualink PDA states that a multiplexer board has to be used if one needs to connect more than two wires to each terminal. I have researched the Jandy part number 6584 multiplexer board and it is quite expensive ($80+) and is nothing more than a small circuit board with four terminal blocks wired in parallel. Has anyone wired more than two RS485 devices without using the multiplexer board? If so, how did you do it?