Add On Instruction / Global Scope Tags

I have an add-on instruction that tracks the run time of our equipment. The AOI has an input called "Reset" which resets the timer.

I want to reset the run time of every piece of equipment in the facility. Ideally, I would like to be able to accomplish this with a single global PLC tag, let's call it "Reset_Run_Timers".

What I could do is have a rung that checks if "Reset_Run_Timers" is energized, and then energize the "Reset" input of every individual run timer in the program. But this means that if I am adding or deleting a piece of equipment, I also have to remember to update my references to its run timer in this rung.

I don't want to maintain a list of references to energize when I need to reset the timers. If AOIs could reference controller scoped tags, it would be trivial. If I could pass in a tag to an AOI as an input parameter it would be trivial as well.

Is there any way around this? How can I affect many AOI instances without all the extra effort to maintain a list of them?

Might be an idea to tell people which PLC you are talking about.......

I am using Studio 5000 with a CompactLogix L36ERM and firmware version 24.

It should be pretty straight forward - In the AOI make your RESET tag a required Input - and on the face of all the AOI's have the RESET Input set to "Reset_Run_Timers"


We do this with all of our blocks to have a global alarm reset command.

DBLD99 said:

It should be pretty straight forward - In the AOI make your RESET tag a required Input - and on the face of all the AOI's have the RESET Input set to "Reset_Run_Timers"


We do this with all of our blocks to have a global alarm reset command.

Click to expand...

Thank you, that is perfect. I was getting in my own way, I should have realized that you can set a tag to be the input on the face of the block even if you can't do it from the properties of the tag.