| 摘要 |
PURPOSE:To decrease the number of sequence controllers without deteriorating reliability by connecting a spare sequence controller to a multiplex transmission line to control a back-up function for troubles of sequence controllers and a test simulator function. CONSTITUTION:The sequence controllers 1A-1C of each system perform transmission/reception of input/output signals with equipments to be controlled via a multiplex transmission line. If a sequence controller working for control has a trouble, a control program equal to that of the faulty controller is stored into a memory of a spare sequence controller 1D. Thus, the controller 1D performs control via the multiplex transmission line in place of the faulty controller. In addition, the controller 1D can serve as a simulator for tests of systems when the programs simulating the working of the equipments to be controlled are stored in the memory of the controller 1D. |
