FUNCTION VERIFICATION SYSTEM OF PLC (PROGRAMMABLE LOGIC CONTROLLER)

PROBLEM TO BE SOLVED: To verify a function of a new PLC (programmable logic controller) using real data without requiring a large-scale and complex function verification device. SOLUTION: The function of the new PLC to be incorporated in a plant in place of an existing PLC 1 is verified. The existent PLC 1, the new PLC and a debugger 10 are connected through a common transmission path 9. The existing PLC 1 transmits input data of remote IOs 3 and 4 and an arithmetic result to be output to the remote IO to the common transmission path by simultaneous broadcasting. The new PLC receiving the simultaneous broadcasting data performs an arithmetic operation using the input data from one of the remote IOs, and transmits the result of the arithmetic operation to the common transmission path by simultaneous broadcasting. The debugger receives simultaneous broadcasting transmission data transmitted by the existing PLC and the new PLC, and compares the data to decide whether the function of the new PLC is normal or abnormal. The debugger includes functions of recording and displaying data related to the result of function verification and alarming depending on the result of verification. COPYRIGHT: (C)2007,JPO&INPIT