| 摘要 |
PURPOSE:To prevent an erroneous control and to improve the reliability of a control output circuit, by avoiding the closure of a contact if a fault arises to a control output circuit of a remote monitor control system which controls the contact open/close of a breaker connected to a power board of slave stations froma master station. CONSTITUTION:Receiving a command from a master station, a CONT1 checks whether a selecting item contact has a fault. A selection relay check signal 7 is first delivered to drive a relay k11. Then terminal points (a) and (c) of a relay contact k11 are closed. In this case, however, no voltage is produced between both terminals of a resistance R1 unless relay contacts k3, k4, k5 and k6 are closed. Therefore a relay k12 is not driven for a voltage detecting circuit 11, and signal lines 15 and 16 have no change of their states. Then the original output operation is carried out by a command given from the master station. While, the relay k12 works if either one of contacts k3-k6 is closed. Then k12 is closed, and the fault is informed to the CONT1 through the lines 15 and 16. Thus a command given from the master station is discontinued. |
