Abstract
A flexible reconstitution distributed control system that has no redundant controller is proposed, and reliability of the system is evaluated.
(1) One controller is connected to a plant by process input/output modules (PMs) and a serial bus which is used to monitor the state of the other controller. A failed controller is disconnected from its serial bus by itself. At the same time, the serial bus of the failed controller is automatically connected to the serial bus of the normal controller which monitors the state of the failed controller. Therefore, normal controllers are able to backup the functions of any failed controllers, so that the system can continue to control the plant.
(2) The system has higher reliability than typical highly reliable distributed control systems that consist of triple redundant controllers or 2 out of 3 redundant controllers, in respect of System Function Reliability (SFR) defined as the rate of survival functions of control system in this paper, MTTF, and reliability.
