Most modular phone cords contain 4 wires that can carry two phone lines (2 wires for each line.) Your system may have either 2 of the wires connected (RJ11 - 1 phone line) or four wires connected (RJ14 - 2 phone lines). The modular connectors on the unit are equipped to handle 4-wire RJ14 connections. If you have a 4-wire system refer to Fig. 1a for connections.

A 2-wire, RJ11 system can be converted to 4-wire, RJ14 system in a number of ways. Check with your telephone vendor or local Radio Shack store for available adapters. A modular adapter to make this conversion sold by Radio Shack is catalog # 279-402. Please note that a simple modular duplicator (Radio Shack #279-357) will not work. Figure 2b diagrams a 2- wire to 4-wire conversion and connection to the unit.