| 摘要 |
PURPOSE:To detect the runaway of a program controller due to the break of a power supply, etc. by providing a means which confirms the execution of a main program in a subroutine program. CONSTITUTION:A microcomputer MP1 is initialized to set a main flag for confirming the execution of the main program in a specific address of the subroutine program. The MP1 once detects a zero-cross signal of power source frequency during processing, starts executing the subroutine program and judges whether the flag set in said specific address is set or not. When this main flag stored in said specific address is set or not. When this main flag is set, the microcomputer MP1 judges normalcy and when not, it is judged that the MP1 is abnormal and a jump to the initial setting of the main program to retry the execution of the program. |
