A Full Automatic Private-Line Teletypewriter Switching System

This paper describes a full automatic teletypewriter message switching system for use in private-line networks involving one or mores switching centers and a multiplicity of local or long-distance lines, each of which may have one or more stations. This system provides fast teletypewriter communication from any station to any other station or group of stations in the network. At its point of origin a message first is perforated in tape accompanied by suitable directing and end-of-message characters, thereafter it is transmitted automatically, stored temporarily in perforated tape at a switching office, and then routed at high speed to its point or points of destination. Important features are the arrangements provided to permit efficient use of long full duplex transmission lines, the full automatic handling of multiple-address messages with only a single originating transmission, and the various guards and alarms which are provided to protect against loss of messages in case of trouble.