Access OPC tags in Control Builder (800xa v6.0)
Hi, I want to access my opc object tags in control builder; I am trying to do this according the method in .doc file (attached). But its not changing value of variable1(snapshot in Help.zip attached) in control builder. Its not even taking substitution value. Also I have provided snap of source expression for my opc tags.
So I want to access my opc tags in control builder, which is not happening. Please have look at attached data and suggest solution.
Thanks!
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Please disregard from the "Is controllable" property - its only needed when writing to PLC Connect (which is part of the MS Word file attached to your query).
I have just verified in my lab that there should be nothing preventing you from Property Transfer a foreign OPC property into an AC 800M Diagram. My test passed with flying colors.
1. Check for Property Transfer errors in the [Workplace Structure]Web System Workplace:System Event List. E.g. a data type conversion error, etc.
2. Consider erasing ALL Property Transfer Definition aspects and start from scratch with just one. We've had issues in the past when one corrupt transfer definition blocked the others. The Find Tool can easily find them if you search for Aspect Category = Property Transfer Definition. The Find Tool also allows you to mark & export them in case you have many and would like to take a backup before deleting all.
3. Can you test to write from, e.g. a Faceplate aspect?
Create a Faceplate PG2 aspect, the assign a bottom row push button to write a known value to the property.
4. Writes can be traced in the AC 800M OPC server by setting the OPCDADEBUGPRINT system variable to TRUE (remember to reset it to FALSE after finishing the troubleshooting, or else the log file will continue to grow...).
The log can be pulled from View->View logfile...
...
I 2015-07-29 07:47:11.580 AsyncWrite (2.0) started: 1 items in AdvDsOPCAdapterGroup6, TransID = 45
I 2015-07-29 07:47:11.632 AsyncWrite finished for TransID = 45.
I 2015-07-29 07:47:11.632 OnWriteComplete sent to client, TransID = 45, HRESULT = 0
...
Answers
Have you enabled the "Is controllable" property in the PLC Connect signal configuration?
If not, you will not be able to write.
In any case, look for Property Transfer errors in the [Workplace Structure]Web System Workplace:System Event List.
Update Rate 0 ms may be too fast. If you see "transaction overrun" warnings the writing takes longer time than the updates, ie a new value is received from source side before last write was completed. Increase update rate until overruns stop.
AC800 OPC server does not permit more than 50 simultaneous writes per group. If you have more than 50 transfer properties sharing group (by having same update rate) writes may fail. Do not let more than 50 properties share same update rate setting. A tiny milliesecond difference is enough to force a new separate group to be created.
Thank you for this topic. It really helped me today in my work! I needed to get an OPC value and send it to a small operator panel via access variables. It worked great after following your attached documents. Thank you! :-)
Regards Joakim xxxx , Automation Engineer on AFRY Malmö, Sweden
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