Telephone exchange with central control - interrogating de-centralised devices so that relay control data is handled before flip=flop control data

摘要

The telephone exchange is designed so that higher priority main operations are evolved at the right time and lower priority main operations are not delayed unduly. The different times needed to execute these operations are taken into account, e.g. flip-flops respond quicker than relays. A central control interrogates decentralised devices and fetches information from them which it uses to control the operation. Interrogation takes place in a time interval divided such that the central control manipulates information for use in controlling, e.g. relays during the first half of this interval whilst in the second half it manipulates information for controlling flip-flops.