| 摘要 |
PURPOSE:To discriminate that an unconnected cable is a cause to the occurrence of an error by conducting the connection check of an optical interface cable in real time through the use of an H/W timer and sending immediately an alarm signal to an opposite station when a cable connection error takes place. CONSTITUTION:When the error of an optical interface cable connection is detected, a counter 8 operated by a clock 11 of a concerned station 2 interrupts an optical interface cable 7 in a cable interruption timing, no counter clear signal 13 is sent and the counter 8 keeps counting operation as it is. When a counted data signal 14 exceeds an overflow value the occurrence of the error is detected and the connection error of the optical interface cable 7 is informed to an opposite station 1 through an interface cable 10 provided separately. Thus, the H/W not having a CPU in the concerned station 2 conducts the cable connection check, the connection error is informed to the CPU of the opposite station 1 and the reliability is improved. |
