Hi, I have a counter tag for which I will be incrementing the values .
Problem is I will be doing this action in tag change of gateway script. as all tags triggered simultaneously , this is causing write conflict and displaying wrong counter value . Do we have any option like to keep tag write in que ? or any other suggestions are appreciated.
Thanks in advance.
What exactly do you want to count ?
If Ignition is the only source of writes, don't use an OPC tag. Use a memory tag, and when you change it, use
system.opc.writeValue() to actually send it to the PLC.
Ignition is connected to MES and based on tag trigger we will be doing some MES API transaction .... likewise we have 80 tags which will run in parallel and will be increment counter post some transactions are successful in each tag. This is counter is wrong every cycle
Sounds like you have an issue with the order of delivery of tag updates from OPC, in that you rely on some order that you are not getting. This is a common failure of understanding how OPC works, and in particular that there is no specified ordering of updates to subscribed tags.
Please share more specific details of what is triggering your transactions, what other data needs to accompany each, and how you need to handle the responses.
And how fast you are trying/expecting this all to work.