Key position evaluator for telephone exchange operator positions - detects when key has been operated and sends data-blocks serially to control unit

摘要

The evaluator cyclically samples the keys of an operator's set and sends the resulting key position information serially as a data block via one or more data highways to a control unit. Each key is assigned one bit placce in the data block. Sampling is controlled by a clock synchronised with the operator sets. The information contained in each data block is monitored by a counter which is updated by an information bit indicating that a key has been operated. The data block is only released for full evaluation when the counter reaches a count corresp. to the quiescent state to the first count step and when the same key information occurs in at least two consecutive data blocks.