| 摘要 |
PURPOSE:To enable to detect the abnormality which cannot be detected by the self- diagnosis function, by detecting whether the running time of the application program or the time interval of running is within a prescribed range or not in the process computer. CONSTITUTION:For the control of the running state of application control program PR2i, the run instruction of PR2i is issued by basic software 1, and simultaneously, the realy output instruction is issued to I/O process PR3, and the output is latched; and when execution of PR2i is terminated to transfer the control to execution of another PR, this latch is released. When relay output contact 4A stored in I/O device 4 is closed by the relay output instruction, on-delay timer 5 of alarm display circuit DR operates; and if contact 4A is held for a prescribed set time or more, contact 5A is closed to issue alarm to warning display circuit AL. If the time from the end of running of PR2i to the start of the next running becomes a prescribed set time or more, on-delay timer 7 operates, and contact 7A is closed to issue alarm to circuit AL. |
