Abstract: Centralized toll restriction for private branch exchanges (PBXs) is performed by providing first and second memory addresses in the number translator of a central office switching system. The first and second addresses are matched with restricted telephone calls and unrestricted telephone calls, respectively. Those telephone lines of each PBX which are to be restricted are marked in a convenient manner, such as with tip to ground marking, while those telephone lines not restricted are left unmarked. Outgoing trunks between the PBXs and the central office switching system are temporarily marked with an unbalance upon going off-hook on a restricted telephone line, in order to transmit restriction indication to the central office switching system.

Abstract: A system and methods are disclosed in which two telephone calls are terminated simultaneously provided that one call is a local call and the second call is a trunk call and further provided that the local call and trunk call originate in separate line units. This is made possible by dividing a central office telephone switching system into two halves wherein each half includes both number translator circuits and code translator circuits and wherein each half includes both local register groups and trunk register groups. An allotter alternates between the register groups in each half of the circuit while indexing the register groups in order to match a local call placed in one-half of the circuit with a trunk call placed in the other half of the circuit for simultaneous termination.

Abstract: A respective bus monitor circuit is connected to each group of a plurality of circuits selectively connectable to one end of a multi-conductor bus which extends to a common control circuit. When the function to be performed by the common control circuit is not completed within a preset time, all bus monitor circuits are signalled to check the group of circuits to which they are individually connected to locate a possible malfunction therein and automatically disable that group to prevent lock-up of the system if the malfunction is detected.

Abstract: A number translator which includes a memory system for storing directory and equipment numbers as well as other subscriber data has a digit store for storing data received from a register prior to its being passed on to the memory system, a register sender control for controlling the sending of data from the memory system to the register and a translator control for controlling both the digit storage and the sender control. The number translator further includes a route translation circuit by which an available outgoing trunk group is selected and an outgoing trunk marker control for controlling trunk selection based on sender availability. Various decoding is also performed in the translator including both calling and called class-of-service decoding as well as office codes and party line identification.

Abstract: A scanner arrangement for scanning both line circuits and incoming trunk circuits simultaneously in groups with priority being given to the scanning of incoming trunk circuits. A sequencing means provides for individual scanning of line circuits of respective groups in which a possible request for service exists and the priority for trunk circuits is effected by inhibiting this sequencing and immediately scanning a selected group of trunk circuits.

Abstract: A method and apparatus are disclosed for providing automatic toll ticketing in a common control telephone system. The method includes sequences which provide automatic ticketing for station-to-station sent paid local or tributary terminations with automatic or operator number identification. The apparatus includes an adapter circuit connected to the common control for directing the transfer of toll information from common registers to a toll buffer. An automatic recorder is controlled by the toll buffer and a plurality of recording trunks to receive charge information and provide a permanent record of the toll charges for the common control system.