The unit will only capture Caller ID when connected to the central office phone lines coming into the building. The unit will not function properly when connected to extension lines from a telephone switch. If your wiring is modular, simple modular splitters will be required to form a "Y" or branch circuit such that each phone line can connect to the Whozz Calling? POS unit in parallel.
If your existing telephone wiring is not modular, consisting of "punched down" solid wire connections, it is recommended that a qualified telephone technician adapt modular connectors for the installation. Figure 3.1, “Telephone Connections” diagrams the parallel connections required for proper installation.
Most modular phone cords contain 4 wires which can supply 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 only 2-wire RJ11 connections. If you have a 4-wire (RJ14) system, consult with a telephone technician to convert them to a compatible 2-wire RJ11 system.
Figure 3.1. Telephone Connections
Even if your telephone system switch is Caller ID capable, it will not pass analog Caller ID. Therefore, the POS series units must be connected to the phone lines coming into the building from the telephone company. These lines are branched (split or half-tapped) and connected to the input jacks of the morning unit. If these lines are not modular, solid wire to modular adapters must be installed.