| 摘要 |
PURPOSE:To prevent a malfunction and to enable a clear input even during trouble by providing a control means which detects the execution of a prescribed operation other than the operation for non-trouble of a clear key to clear a set number during a trouble. CONSTITUTION:A trouble detection signal ERROR is inputted to a multiplexer 23, and a set count number is outputted to a comparator 22. A set count number A during trouble is larger than a count number B in an ordinary state. Consequently, the clear key must be depressed continuously for a time longer than that of depression in the ordinary state in the case of the clear input during trouble. This switching is possible in software by a program. Since the clear input during trouble is made difficult more than that at the ordinary state in such a manner, the erroneous operation during the trouble processing is prevented, and the set number can be cleared even during trouble as necessary. |
