| 摘要 |
<p>PURPOSE:To obtain the highly reliable and superior controller by performing the same operation as normal operation by a 2nd timer which substituting for a reference signal even in the case of input trouble of the reference signal. CONSTITUTION:If a signal which is inputted from the reference signal 1 is ceased owing to some cause, a signal generator 2 generates no signal output and no request for interruption is sent to a microcomputer 3 (t4). A 1st timer 4 is not in a reset state a constant time later to enter a set state and the microcomputer 3 is interrupted in response to a time-out state. Namely, when the interruption is caused, the 2nd timer 5 is initialized and then a signal switch 6 is so switched as to apply the output of the 2nd timer 5 to the microcomputer 3 (t5). Then the 2nd timer 5 outputs a control signal instead of the reference signal 1 and normal processing wherein the microcomputer 3 performs control is entered. Consequently, the operation of the controller is carried on and the highly reliable controller for VTR, etc., is obtained.</p> |
