| 摘要 |
PURPOSE:To inhibit the driving of a device to be controlled when a microcomputer has some fault, by installing a decoder to detect a series of prescribed sequence plus a sequence circuit containing a series of FF that stores in a normal way the above detection of sequence. CONSTITUTION:With a normal operation of the microcomputer, the operation of a program progresses to set ''1'' at the FF9 and then decode 3 the address 13. As a result, the data is written into the FF9, and the output of the FF9 is set at ''1''. On the other hand, the signal 14 is supplied to the MON-FF4. For the FF4, the output 19 is set at ''1'' in accordance with the time during which the computer 1 executes one reading cycle, and then the output is turned to ''0'' when a prescribed time elapses. The MON-FF5 is set at ''1'' by the pulses that are generated for the period during which the output 19 is changed to ''0'' from ''1'', and the output of the FF10 is set at ''1'' by the pulse produced for the time during which the MON-FF5 is set at ''1''. Thus the rotation signal of a motor can be set first, and the driving of a device to be controlled is inhibited when the computer 1 has some fault to secure the safety. |
