INSTRUMENTATION CONTROLLER

PURPOSE:To detect the abnormality of a control response and to quickly stop the control system by generating an abnormality signal and giving a stop command to the control system, when a process value inputted to a sensor monitoring means at the time of control mode is different from a deviation of a fluctuation of a process value stored at the time of leaning mode. CONSTITUTION:When a control state is normal, the device is switched to a learning mode and from collected process data, a deviation value in each control pattern, a response time of control to a change of a set value, and the settling frequency until a deviation of a set value SV and a process value PV goes in within a prescribed value are derived and stored in each table. Subsequently, whether the deviation of the fluctuation of the process value PV inputted at the time of control mode, the response time and the settling frequency exceed the data concerned of each table 10, 12 and 14 or not is decided, and in the case of abnormality, a stop command is given to a control system. In such a way, an abnormality detection can be executed quickly against abnormality of a sensor itself, disconnection of a sensor signal transmission line, etc., and also, the detection can be executed even against control response abnormality and tuning abnormality, and the control system can be stopped before executing the abnormality control.