| 摘要 |
PURPOSE:To confirm the 2nd dial tone without transmitting a PB signal to an opposing station, by providing incoming and outgoing terminals for a PB register installed in an automatic branch of exchange and connecting a single way amplifier from said incoming terminal to the outgoing terminal. CONSTITUTION:A register PBR is provided with outgoing/incoming terminals (a), (b), and the connection is made at signal conversion from the terminal (a) to a caller PBTEL via a bus 1 of a switch SW0 and from the terminal (b) to an outgoing trunk COGT via a bus 2. The PB signal received at the register PBR is given to a central processing device CC and a main trunk COGT via a DP center DPSDR and a switch SW1. The register PBR with such connection is connected with a single way amplifier D from an incoming terminal L to an outgoing terminal T, and the transmission to the opposing station of the PB signal from extensions is blocked with an amplifier D from the terminal L via a truck COGT. The 2nd dial tone of the opposing station is inputted to the terminal L through the trunk COGT and the bus 2 for confirmation. |
