We are trying to use ignition to data log from a barcode scanner. We also want the ability to if a barcode is scanned twice to write back to the plc with an error. Is this possible within ignition?
Warning— I am a little new to ignition
Thanks fro the help
Yes, it’s possible.
I admit it, I was feeling a bit snarky there. I was going to leave it there, since there’s not a lot to go on, but here’s my take on it. (My view is from a manufacturing standpoint)
First, though, welcome to the forums! Don’t let my lack of sleep or caffeine trouble you.
At the beginning of the cycle, it should be assumed the part is bad until told otherwise from the process. It’s the same with duplicate scans.
I would do this with a transaction group.
-
The scan comes in as a read-only item.
-
A query expression item to check if there are any duplicates. If it returns 0, there is no duplicate. More than 0 is a problem.
SELECT count(*)
FROM table
where barcode = '{new_scan_item_in_group}'
This is just a rough outline, but a transaction group, IMO, is the least painful way to go.