TI505 Cascading Edrum Help

[omegablue333 0]

I'm doing a project in school and have to cascade two edrums in a certain pattern. I can get it to work when the outputs arn't the same on both drums, but as soon as they are, the second drum seems to over power the first so that it doesn't work. I've heard it has something to do with the memory? Please help ASAP

[Ken Moore 23]

TI plc's scan thier logic from top to bottom, left to right. After the end of the scan the outputs are updated. So if two instructions are addressing the same output (which is not recommended), the last one in the scan will always win. The output will be updated to the last scanned value. You should have your drum output tied to coils, and then use the coils to drive the physical output. Then you can use conditional logic to select which coil has control ie....If drum1 active then C1 drives Y1 if drum1 inactive and drum2 active C2 drives Y1 etc... Ken

[omegablue333 0]

thanks ken. Worked great. Kinda dumb that I didn't think of that first