| 摘要 |
PURPOSE:To make a complicated switching part and etc. unnecessary and to back up the control automatically with a simple constitution, by taking all signals on a transmission line into a waiting operation control part and executing the control operation in this operation control part synchronously with the signal transmission of the current operation control part and performing the control operation immediately when the current operation part is faulty. CONSTITUTION:Signals from a process field 11 are inputted to plural input and output parts 12-14, and output data of input and output parts 12-14 are taken into operation control parts 16 and 17, and outputs of control parts 16 and 17 are outputted to output lines 18 and 19 respectively. These output lines 18 and 19 are connected to respective fixed contacts of a switching part 24, and the movable contact of the switching part 24 is connected to input and output parts 12-14 commonly. Unidirectional signal transfer elements 25 and 26 are connected between output lines 18 and 19 and input and output parts 12 and 14. One control part 16 or 17 is operated as the current control part, and all signals are taken into the waiting control part successively on a basis of the indication of the current control part, and the control operation is performed synchronously with the signal of the current control part, and the control operation is performed immediately when the current operation part is faulty. |
