DSU HANGUP RELEASE APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a DSU hangup release apparatus capable of surely releasing hangup independently of variations in characteristics among DSUs. SOLUTION: The DSU hangup release apparatus 10 comprises: a detection circuit 12 for detecting a burst frame transmitted from the DSU 20 to a host station; a monitoring timer 14 for monitoring an elapsed time after the burst frame is not detected and outputting a time-out signal when the elapsed time reaches a limit time; a reset control circuit 13 for outputting a reset signal to release the hangup state to the DSU 20 when the timer 14 outputs the time-out signal; and a counter 15 for counting the number of output times of the reset signal, and the reset control circuit 13 outputs the reset signal again to the DSU 20 at the output of the time-out signal when a burst frame non-detection state is consecutive even after the output of the reset signal and stops the output of the reset signal when the number of output times reaches the number of upper limit times. COPYRIGHT: (C)2005,JPO&NCIPI