JPS5571347A - Interphone unit - Google Patents

Abstract

PURPOSE:To set one operation part to a service state in preference to other operation parts by making it possible that an arbitrary slave equipment is called easily from any master equipment-side operation part by the line control part where plural slave equipments are connected. CONSTITUTION:Circuit control part 2 is connected to operation parts 1A and 1B having service key T, transmitter-receiver HS and display part D to constitute an interphone unit. Signals of office number set keys K1-K2 of operation parts 1A and 1B are stored in register 3 of control part 2, and contents of register 3 are read out into decoder 4 by service key T, and signals are decoded to select a service slave equipment by service state detection gate G4. This selected signal is applied to FF-A and FF-B which make operations of operation parts 1A and 1B, where office number set keys K1-K2 of operation parts 1A and 1B are not operated, impossible through gates G1 and G2 which select operation parts 1A and 1B, thus setting selected operation parts 1A and 1B to a service state preferentially.