Private branch exchange

Abstract

Abstract PURPOSE:To make a direct call to an extension telephone set even from a rotary dialing telephone set by converting dial pulses of an additional dialing signal transmitted by an included telephone set into a push-button dialing signal and transmitting it. CONSTITUTION:When a central office trunk is acquired by the trunk line origination of a rotary dialing telephone set DPSTA and dialing operation is performed by the DPSTA, it is counted by an originating register ORT and a CPU controls a dial pulse sender DPSD, so that a dial pulse signal is sent out of the COT to an office. When the CPU detects the number of digits of the called subscriber number and the completion of dialing of all digits is confirmed by the originating extension, the DPSD is released and a push-button signal sender PBSD is acquired and connected to the COT. When a called extension number is dialed, the CPU connects the PBSD connected to the COT to convert the dial pulse signal generated by the dialing operation of a calling subscriber into a push-button signal, which is sent out to an incoming-side private branch exchange.

Inventors

• 👤 Masahiko Abe
• 👤 阿部　政彦

Bibliographic Details