Patent ID: 7613108
Filing Date: 2009-11-03
Classification: G05B

Abstract:
1. A redundant supervisory control system having a pair of network loops in parallel in a single loop network, comprising: a pair of controllers each collecting input data from a controlled subject, and outputting control data based on the input data; a plurality of remote input/output units each connected to both of the pair of network loops in the single loop network for collecting the input data from the controlled subject, transmitting the input data to both of the controllers, and outputting, to the controlled subject, the control data transmitted from an active one of the pair of controllers currently executing control; communication cables each connecting the pair of controllers and the plurality of remote input/output units to make the pair of network loops in parallel; and a pair of redundant control interface units for mutually monitoring abnormality statuses of the pair of controllers, and setting a control right allowing any one of the pair of controllers to execute control in an active state, and the other controller to be in a standby state, and the redundant supervisory control system being configured to control the controlled subject by performing communications in two directions of clockwise and counterclockwise in each of the pair of network loops in the single loop network composed of the pair of controllers, the plurality of remote input/output units and the communication cables, in accordance with a predetermined communication protocol, wherein each of the pair of controllers includes: wherein each of the plurality of remote input/output units includes: when a reception failure is detected in at least one portion on one of the pair of network loops including one or both of the pair of first loop interface units and one or both of the pair of second loop interface units in one or plural remote I/O units, one or plural first loop I/F units capable of normally communicating and one of the pair of second loop I/F units in one or plural remote I/O unit, capable of normally communicating are automatically selected, so that transmissions are performed in one or both transmittable directions of each of the pair of network loops; and in a case where plural failure portions of the respective network loop do not overlap with each other, each of the portions starting from each of the pair of controllers, and ending at a location of a failure, the control is able to be continued without switching the control rights.