| 摘要 |
PURPOSE:To surely prevent a misoutput to an unexpected control device at the recovery of a failure, by constituting so that the lock can not be released as far as a reset switch is not operated, when a sequence controller has no failure. CONSTITUTION:If a sequence controller or its external circuit has a failure, a contact 25 or 26 is closed. When the operator judges the stop of sequence control, a switch 27 is closed. Then, a relay 29 is operated and the self-holding of a relay 28 is released by open contact 29b and a contact 28b is closed. Then, an output lock signal is given to each bit of an output register, each bit is compulsively reset with the signal and an output to a control device is locked. Next, when the operator depresses a reset switch 24 after the confirmation that the failure is completely removed, a self-holding circuit of the relay 28 is formed, the contact 28b is opened and the output lock of the sequence controller can be released. |
