| 摘要 |
<p>PURPOSE:To surely detect the failure which is logicall impossible, by performing the check of the states of all of output confirming devices in the respective motion steps of the upper stream motion block continued to one motion block, at the actuation time of the ladder program of this motion block. CONSTITUTION:In the case of a block hang-up being detected because of a block 4 being not actuated, the motion step of the cause exists in either block 2 or 3. AS for the block 4, output Y1-Y4 are turned ON in the block 2, and even confirmation switches X1-X4 are turned ON. Also, in the block 3 output Y4-Y7 are turned ON, and even confirmation switchs X4-X7 are turned ON. Therefore, it should be X1*X2*...*X7, when the block 4 is normally actuated. The blocks 2, 3 are actuated by the completion of the block 1. Therefore, the actuation conditions of the block 2 and blocks 3 become the AND of the state of the confirmation switch of all motion steps of the block 1.</p> |
