Improvements relating to arrangements for automatically identifying calling numberspertaining to calling lines in telephone systems, and for automatically deriving other information pertaining to such lines

1,004,572. Automatic exchange systems. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. July 2, 1963 [Aug. 10, 1962], No. 30760/62. Addition to 997,343. Drawings to Specification. Heading H4K. In the calling line identifying arrangement of the parent Specification, to provide a 2-out-of-5 output code, the decimal output wires are each taken directly to two multi-stage transistor amplifiers of which the first stage is a normally conducting transistor which is brought to cut-off by the relevant marking condition. A pulse generator incorporating a timing relay is described for sending identification and class of service signals to a toll switching centre in accordance with the stored information. If for any reason the caller is not identifiable, e.g. in the case of certain multi-party lines, a signal is given to a check operator store to route the call to an operator at the toll centre. A validity checking arrangement may be provided as described in Specification 924,491.