Explore PLC tag list in a generic manner

[Jochen Haar]

I found  the libplctag last weekend and played a little bit around. Congrats to the provided work - it is really great.

What I was wondering about is, if and how it is possible to explore the complete tag list of the controller as a tree list. UDT's can have nested UDT's and so on.

Is it not possible to create such a tag list on different levels? E.g. if you start from the root, to get the complete tag list. If you start from an UDT to get the UDT tag list?

I have attached an eip-modified class which I used in other projects, maybe this one explains it a little bit better.

Thanks for any comments

[Kyle]

Hi,

Thanks for the interest in the library.   Unfortunately, Rockwell/Allen-Bradley does not make it easy to get the full information about the tags in a PLC.   Currently, the core C DLL supports just tag listing.   I am currently working on ways to support raw CIP (the command protocol used by newer AB/Rockwell PLCs) so that tags can be listed and UDT definitions can be retrieved from the PLC.   At the underlying PLC level it is not as simple as listing within each UDT.

Search for Rockwell document 1756-PM020G-EN-P.  It describes how to retrieve tag listing information and UDT descriptions from a PLC.

Please reach out to the libplctag.NET project (part of the libplctag organization) for any .Net use.

Best,

Kyle