JPS6450697A - Key telephone system - Google Patents

Abstract

PURPOSE:To output a hooking pulse with respect to a supplementary line wire by dialling an access code outputting the hooking pulse with respect to hooking and the line wire when an individual line telephone set is in the middle of call with the line wire. CONSTITUTION:When the hook switch 10 of the individual line telephone set 2 is depressed and hooking operation is executed, an individual line telephone set interface 5 detects a hooking signal, transmits a detection signal to a main control part 4 and transmits an instruction for holding a line wire concerned 3 in a line wire interface 6 to a channel switch 7. When the access code (' ', for example) is dialled by the individual line telephone set 2, the main control part 4 transmits an instruction signal for outputting the line wire hooking pulse to the line wire interface 6, simultaneously transmits the instruction for returning the having held line wire 3 to original call to the channel switch 7, and connects a channel with the individual line telephone set 2 in the middle of operation so as to return a system in a call state.