Control system for industrial plant

Claim 1

A control system for an industrial plant comprising a plurality of instrument sets and a plurality of logic sets, each instrument set comprising: a plurality of sensors to detect parameters of the industrial plant, each instrument set also comprising a plurality of serial link controllers, each sensor being arranged to supply an output signal to each of the plurality of serial link controllers, each logic set comprising: a plurality of auto select logic circuits, a synchronizer, a voting logic circuit, a serial-to-parallel converter and a control logic circuit, each of the plurality of serial link controllers in each instrument set being arranged to supply the output signals from each of the sensors in the instrument set sequentially to a respective one of the auto select logic circuits in each of the logic sets serially via respective independent transmission lines, each of the auto select logic circuits in each logic set being arranged to select data form the plurality of sensors from the respective one of the instrument sets and being arranged to supply the data to the synchronizer, each of the auto select logic circuits in each logic set being arranged to detect any of the respective independent transmission lines transmitting erroneous serial signals and being arranged to select one of the independent transmission lines not transmitting erroneous serial signals, the synchronizer of each logic set being arranged to supply the data from each of the auto select logic circuits to the voting logic circuit of the logic set such that the output signals from the sensors in each instrument set detecting the same parameter are supplied to the voting logic circuit at substantially the same time, each voting logic circuit being arranged to perform a voting function on the output signals from the sensors in all the instrument sets detecting the same parameter to produce a series of single high reliability signals which are arranged to be supplied to the serial-to-parallel converter of the logic set, each serial-to-parallel converter being arranged to convert the series of high reliability signals to parallel high reliability signals which are supplied to the control logic circuit of the logic set, each control logic circuit being arranged to control the operation of the industrial plant in response to the high reliability signals.