PURPOSE:To prevent an important signal from malfunction even if softwave runs away by executing respective program tasks independently and sending output information in accordance with respective program tasks. CONSTITUTION:A task schedular 7 makes the program tasks 5, 6 execute alternately at 100ms period by a time interrupting method or the like. If an output signal 3 is set up to ''1'' and sent in error when a processor 1 executes malfunction due to noise or the like, a program runs away, the program task 5 executes a step for setting up the outut signal 3 to ''1'', and an input signal 2 is ''0'', the execution of the program is returned to the task schedular 7, so that the program task 6 is executed from its head and an output signal 4 is not turned to ''1''. Thus both the output signals 3, 4 are scarecely set up to ''1'' simultaneously.

Abe Hiroaki

Papers

Guard processing method of important signal