SYSTEM ABNORMAL PLACE DISPLAY SYSTEM OF PROGRAMMABLE CONTROLLER SYSTEM

PROBLEM TO BE SOLVED: To increase safety of control of a system by resetting a module at need when resetting a CPU by a watchdog timer.SOLUTION: A programmable controller body includes the CPU 7 which executes a control program and has a watchdog timer function of outputting a system failure pulse for system failure, a reset circuit 9 which outputs a forcible reset signal to the module 2, and an operation state display device 11 which displays system failure as an error display. The CPU 7 forcibly resets the module by driving and controlling the reset circuit in case of a system runaway, and also controls the system abnormal state device to display the system abnormal state with an image.