Studio 5000 - Checking multiple equipment AOIs for manual state

[rupej]

My work has set up AOIs for individual pieces of equipment like a valve AOI, pump AOI, etc that contain bits for HOA state. I'm trying to find a clean way to check every AOI to see if any are in a manual state, and energize an "Output in Manual Warning" bit that I will display on the HMI. Of course I could just do huge parallel XIC rungs for every piece of equipment, but it's tedious with hundreds of items, and people forget to add them when new equipment is added.

My first thought was to set up an "Output in Manual" bit as an output parameter for each AOI instance, and pass a "Output in Manual Check" bit to each AOI, which would then latch the "Check" bit if it was in manual. At the end of the program scan, if the "Check" bit was on, I would energize the "Output in Manual Warning" bit and then unlatch the check bit for the next scan.

The problem I've found is that the AOI cannot latch an external bit, it just latches its own internal parameter tag that the external bit is tied to. This means that I can't pass a "Check" bit, because it will be overridden by the next AOI's state, and I'll only be able to see the state of the last AOI.

Has anybody ever implemented something like this? Any ideas?

Attached is what I'm trying to achieve, but I'd like to do it within the AOI itself.

 

[jstolaruk]

You can latch an external tag if its passed by reference (in/out parameter when declared), I do it often. Mine is usually in a UDT with a bunch of other status bits that I use so that AOIs can pass information or status back and forth; the udt tag instance is passed by reference (in/out).

 

[cwal61]

Instead of using bits why not use a DINT and an ADD instruction inside the AOI. If the AOI is in Manual then Add 1 to Manual Check DINT. I am thinking of the Brute force method. At the Beginning of each scan CLR DINT then each AOI add 1 to DINT if in Manual. Not only would you get AOI in Manual but how many are in manual.
OR
If Manual DINT <> 0 then Manual Check Bit True

 

[rupej]

Thanks to both of you. I'll give the in/out parameter a try and also I like the DINT idea!