Generic OPC Object: Need to Reference Control Connection Properties (not Objects)
I created a Generic OPC network in Control Structure for an Allen Bradley PLC RSLinx OPC server and used Uploader to add the OPC items for U-12 PLC. I added my own RSlinx OPC Object Type and have succesfully added objects to the Functional Structure with the same name as the branches in the RSLinx OPC structure, so that the uploader automatically connected the two. But this is not what I want because I have problems:
1) I do not want to access the OPC "branch" objects, I want to access the OPC property items of the main OPC "online" branch.
2) I do not like the names of any of the items coming over OPC from the PLC and want to give them different names.
So I created a new OPC item in the Functional Structure with a different name and copied the control connection for "online" to it, but now it cannot find the OPC Data Source Object. Does anyone have any suggestions? I tried copying the OPC Data Source Definition to the Functional Structure with no luck. I do not want to create an object named "online" and us uploader again to get the Control Connection because this name is common to both PLC's on my OPC network. Screenshots attached. Thanks in advance.
>" I do not like the names of any of the items coming over OPC from the PLC and want to give them different names.
Does anyone have any suggestions?"
Dont do this. There are many reasons but basically ...
- It doesnt work
- Somebody else is going to spend hours or days figuring out how your 800xA properties relate to your Allen Bradley PLC properties.
The "Control Connection" aspect requires the complete path to the original data point in the third party OPC server and it creates this by using the 800xA control structure object path. So you cannot copy the aspect to another object because you break the path.
If you really need this kind of extra flexibility then you will have to use PLC connect.
>"I do not want to access the OPC "branch" objects,"
You dont have to create objects for everything in your functional structure. Just create objects in the functional structure that match the things that you want to control in your Allen Bradley PLC. Only those objects will get the additional faceplates, gaphics, elements, etc that you created for that object type.
You still have to upload everything in the control structure.
As Rob say, your objects should be located in the control structure. In this structure, and only here, you have the opc definition (opc source). If you need the object in your functional structure for some reason (like alarm lists for areas e.g.) you create a link. (Insert Object, browse to the object in the control structure, insert)