Direct Soft SET / RST question....

Hello all,
Simple question here. I know that one should never use the same output more than one time and if someone were to than the last state of that output in the last rung will control it. But what about SET and RST's. I know they can be used in more than one place and work. Would this be considerd a bad programming practice? Even though it seems to work can it cause issues in the program?
Thanks,
Micheal

Like everything, if you do it right, it doesn't cause a problem and is very useful. I do it when running through the various functions of my program to set warnings and faults, or to sense a particular global condition that is to be used by other components.

For instance, I wrote a program once that had a series of about 50 conveyors. When the machine was in maintenace mode, it was permissible to operate only one conveyor at a time. As I looped through the logic, if there was already a conveyor running, I would set a "Conveyor Already Running" bit that would inhibit all other conveyors.

Just line an OUT, the last instruction (SET or RST) encountered on a true rung in an active section of the program (just in case you are using Stage Programming) wins.

When using Stage Programming it is a permitted (and even expected) programming style to have multiple occurances of the same OUT. Just as long as only one stage containing the OUT is active. Otherwise the 'last one wins' rule is in effect.