Multiple signalling device - for evaluation of state changes of signals from different signal transmitters which are recordable as series signals

摘要

The apparatus has a new signal store for new signal storage, and an old signal store taking over state signals from the new signal store. A comparator assimilates the state signals in the two store. When a difference has been detected, a signal characteristic for the change and a message are delivered, together with automatic acknowledgement signal informing of the signal transfer from the new to the old store. The old signal store (2) is controlled for interrogation of all received messages, so that all storage locations take a state corresponding to a current message.