| 摘要 |
PURPOSE:To transmit efficiently supervisory and controlling information while switching to and transmitting with a main communication channel having a faster speed when lots of supervisory and controlling information are to be sent due to a fault or other cause. CONSTITUTION:When supposing that a fault takes place in a system component 7 at a remote location, the state of the fault is sent to a supervisory controller 1 installed in the vicinity while a sub communication channel is used as a channel. In this case, the operator changes over manually a changeover switch 6 so as to give supervisory and controlling information via a main channel 4. In this case, the path for the supervisory and controlling information is shown in the arrow. The changeover switch may be switched manually by the communication between operators in standby respectively in the vicinity and a remote location and switched automatically by a command from the supervisory controllers 1 recognizing faulty information. The connection between the system component 7 and the main channel 4 is disconnected while the supervisory and controlling information is sent via the main channel 4. |
