DEVICE FOR DETECTING AND RECOVERING TRANSIENT TROUBLE OF TRANSMISSION LINE

摘要

PURPOSE:To prevent the repetition of constitution and removal of an alternative path, by making each transmission control device know addresses of its own device and a paired transmission control device so that an intermittent transmission error can be detected. CONSTITUTION:A transmission control device which detects abnormality of a transmission line and its paired transmission control device which is requested to make small loop check, transmit small loop check data to which their addresses are respectively added to a loop circuit together with received data SA and SAO. When they receive small loop check data from a loop ring circuit, the devices decide the received data SA and, when the data have their own addresses, update a one round data number counting counter 86. When they receive data from the loop circuit, they discriminate the received data SAO and, when the data SAO do not have their own addresses, lecide the data SA. When the data SA have the address of the paired transmission control device, the devices transmit the data to the loop ring circuit. When the data SA do not have the address of the paired transmission control device, they send the data to the loop ring circuit and, furthermore, they generate small loop check data by checking the content of a counter 85 and send the generated data to the loop circuit.