| 摘要 |
PURPOSE:To protect a device to be controlled from errorneous control, by discriminating the malfunction of a control part to reset the control part when the phase relation between the detecting output and the synchronizing signal is shifted and disturbed. CONSTITUTION:Since a detecting signal of a specific pattern is output at a constant interval when the operation is normal, the detecting signal (a) of the specific pattern is output from a control part 1 in a position other than the normal position if the time to the next specific pattern output is shortened or extended due to program runaway, etc. This abnormality is detected by the shift of the phase between the signal (a) and the synchronizing signal (b) in a detecting circuit 4 and an NAND gate 7, and the abnormal operation is recovered. If another control signal is output from the control part 1, the control signal from an output line 3 of the control part 1 is latched in a latch 10 by the latch signal from a output line 9, and this data continues to be output to a device 2 to be controlled until the next latch signal is generated. |
