OPC Clients Can Sometimes Display GUIDs For Item IDs
There may be situations when you use an OPC client (for example, AdvDsOpcClient.exe, AspenTech IP21, PI, etc.) to connect and read data from PPA, and you are greeted by GUIDs for the Item Names instead of more friendly paths. This does not affect the client's ability to subscribe and receive good data quality.Symptoms:
Internal to 800xA, the forward slash characters ( / ) are interpreted as */* (beginning and ending with a wildcard). This makes it easy to have duplicate Item IDs without it being obvious.
Let's assume the following two objects exist:
When a subscription is made to [Functional Structure]Root/Test/SameName:X, it appears as GUIDs.
When a subscription is made to [Functional Structure]Root/Test/SameName/SameName:X, it appears correctly (i.e. name/path syntax).
The reason the first object appears as GUIDs is because its path (including implied wildcards) is duplicated in the second object's path, and the system returns the GUID syntax to make the path unique. The second object is not affected because its path is too long to match the first object. .
Put another way:
When there is more than one possible path with the same name, PPA will present the item as GUIDs.
The expression Root1/Parent1/Child1 will match all of the following paths, due to the implied wildcards:
To avoid this behavior, you must rename the object or others in the tree so that the path becomes unique.