It is constituted combining with the wireless call unit null door phone slave and the interphone telephone machine and the interphone sub- telephone machine of 1 or more which it is increased are added

摘要

PROBLEM TO BE SOLVED: To provide an interphone system where a registration setting operation of a wireless transmitter is available for a master set or a sub master set only when the wireless transmitter is extended newly as a call switch. ;SOLUTION: A wireless call unit 4 that transmits a connection command at a prescribed time interval is connected and added to an extension line L led out from an interphone master set 1 and an interphone sub master set 2 as an extension terminal. When the interphone master set 1 and the interphone sub master set 2 receive the connection command sent from the wireless call unit, the interphone master set 1 and the interphone sub master set 2 effectively function a series of registration setting operations to be assigned to the wireless call unit 4 in an extension registration setting operation mode.;COPYRIGHT: (C)2001,JPO