Redundant process control system

摘要: Sensors (SEN1,2,3) monitor, in parallel, a parameter from the same part of process, producing input signals (E1,2,3) digital form analogue to converter (EIN1,2,3). The are fed individual programable logic controls (PLC) and memory units (MEM1,2,3) linked test (TES1,2,3). Output (S1,2,3) produce control (R1,2,3) which compared comparator (SEC) an actuating signal (CL) based on majority voting i.e. comparing all for variation value accepting two or three similar as true value. actuate regulator (REG) activate action process (e.g. valve opening or, emergency, shut down). with information PLC's output response (E). and, if different, generate alarm (AL1,2,3). supervision unit (SUP) compares inputs decides activation emergency (EM) using system described (SEC). Network connections provide overview activity.