Low Level View of ABB PPA’s Object Structure

This articles serves as the sequel to my previous one about opcguid utility. In essence, the purpose of this utility is to show the GUID of arbitrary names. This GUID can be used for various purposes such as finding the internal names of certain tag id on OPC server.

The utility will return 0x80004005 when performing the exact search and it can find none on existing ABB PPA’s objects directory :

In the above case, there is no exact match for “t13” name in the directory.

This utility also accepts wildcard search such as :

In this case, the utility will just show the GUID of the first element that matches the wildcard criteria (i.e. *T13*).

But here comes the question as to what’s the object name that correlates to the above GUID of {8B44BCD6-8D6A-4B4D-8F78-3BDD652EECA8}.

There are two kinds of approach to answer the above question, i.e. by utilitizing some ABB internal methods, if any, or perform direct search to the existing object structure. I will now explain the second approach.

The GUID can easily be located using some file searching utilities such as winhex and the above GUID actually resides in many of the object structure files located in C:\OperateITData1\AspDir\Categories, depending on the ABB PPA’ s data directory setup.

Inside the “Categories” directory is the collection of files that contains the object description about each category in the form of {GUID}.dat.

For example, the file {9879EB4B-87FA-11D1-B1E0-0060B017F346}.dat contains collection of names that fulfill the wildcard criteria for *T13*.

The mapping between *.dat file inside Categories directory and its description is located inside ObjMgr.dat. This file resides in C:\OperateITData1\Temp\AspectDirectory. For the above *.dat file the description is “Name” :

You can find the description of any guid of *.dat inside category directory inside ObjMgr.Dat.

Now let’s view the {9879EB4B-87FA-11D1-B1E0-0060B017F346}.dat for the corresponding of the above GUID :

You can see that the answer of the above question should be “T13 Sample” 🙂


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