| 摘要 |
PURPOSE:To switch the current line to the stand-by line rapidly when the current line is abnormal, by sending the switching command through the stand-by line or another switching command line. CONSTITUTION:Receiving circuit 14 is connected to current line 11 by switching contact 13. When abnormality occurs in line 11, the switching command transmitted to terminal equipment 18 through stand-by line 12 is received by receiving circuit 15, and contact 13 is switched through relay circuit 16. Since lines 11 and 12 are arranged on different routes, a fault as prevented from occurring in lines 11 and 12 simultaneously. |
