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Technical support / Re:Ladder outputs not executing
« on: November 23, 2008, 08:36:33 PM »
OK, here's a simpler example:
If I have a rung that has a latch and unlatch as it's outputs. There seem to be two issues here:
1. Sometimes the result seems dependent on the ordering of the outputs if they are included in the rung condition. For example if I have a run condition containing x, if I clear x as the first output, the second output doesn't seem to run. This is incorrect as once a rung condition is true all outputs of the rung must be executed. The rung condition should not be reevaluated until the next cycle.
2. Sometimes a second output of a rung isn't run whereas in others it is. In my current code I have some rungs that I have had to split into two as they don't work, whereas similar rungs do in other parts of the code. This seems to change as the surrounding code is modified and I can't find a general pattern as to why.
This behaviour has caused me much confusion and slowed my development down considerably.
If I have a rung that has a latch and unlatch as it's outputs. There seem to be two issues here:
1. Sometimes the result seems dependent on the ordering of the outputs if they are included in the rung condition. For example if I have a run condition containing x, if I clear x as the first output, the second output doesn't seem to run. This is incorrect as once a rung condition is true all outputs of the rung must be executed. The rung condition should not be reevaluated until the next cycle.
2. Sometimes a second output of a rung isn't run whereas in others it is. In my current code I have some rungs that I have had to split into two as they don't work, whereas similar rungs do in other parts of the code. This seems to change as the surrounding code is modified and I can't find a general pattern as to why.
This behaviour has caused me much confusion and slowed my development down considerably.