LOOP CONTROL APPARATUS

A loop control apparatus for controlling general process control such as control of the temperature of water supply comprises an interpreter for interpreting input information in the form of trains of characters to provide instrument information and a compiler for interpreting the train of character and compiling therefrom operational equation information. The trains of characters are inputted from an external general purpose computer as a man-machine interface through a serial interface provided within the loop control apparatus, and are subjected to word analysis and syntax analysis by the interpreter and the compiler. Loop control function information produced through the word and syntax analysis is stored into a memory means. Once the instrument design and the operational design have been completed, the interface computer is not needed and can thus be used for other jobs not related to the system under control. When controlling the system, a control means processes the process values of the system in accordance with the loop control function information to provide manipulate values to thereby perform the loop control of said system.