The conservative information transmission mode null in the deijitaru multiplex

摘要

PURPOSE:To quickly and surely execute transmission/reception of a signal requiring urgency such as maintenance information by providing a means sending the maintenance information on a specific channel and a means detecting the sent maintenance information stably. CONSTITUTION:A maintenance channel 14 is provided, and maintenance information transmission/reception circuits 7, 8 using the channel for mutual transmission/reception are provided, and an output of a parity check circuit 31 is logical '1' without production of parity error and logical '0' with the presence of a parity error. Thus, if an error is detected as the result of parity check when each signal bit passes through AND circuits 40-46, the output of the AND circuit 45 is logical '1' and the other AND circuits 40-44, 46 give logical '0' output fixedly. The signals are given respectively to signal detection counters 50-56, from which maintenance information 60-66 is outputted.