Beckhoff's TwinCAT platform lends itself to git pretty well, there are XML stuff on most files, but it's mostly readable as long as you use STL (Structured Text) which is their recommended language.
Siemens's TIA Portal you can export the source code to make it readable in git as long as you code in SCL (structured control language, which is really structured text), but it's not automatic and a lot of times the binary blob that is the source code and the exported readable code get out of sync cuz of lack of discipline by the programmer.
Rockwell's Studio 5000 can be readable if you use STL (structured text), may be this has changed though, I haven't used it in a long time.
Programming experiences in the industrial controls world is highly dependent on the brand/platform, the IEC 61131-3 describes the standards for industrial controls programming languages, but each brand implements them in a different way so there really is no standard. Writing structured text in one platform does not guarantee the same code will work in a different platform.
Siemens's TIA Portal you can export the source code to make it readable in git as long as you code in SCL (structured control language, which is really structured text), but it's not automatic and a lot of times the binary blob that is the source code and the exported readable code get out of sync cuz of lack of discipline by the programmer.
Rockwell's Studio 5000 can be readable if you use STL (structured text), may be this has changed though, I haven't used it in a long time.
Programming experiences in the industrial controls world is highly dependent on the brand/platform, the IEC 61131-3 describes the standards for industrial controls programming languages, but each brand implements them in a different way so there really is no standard. Writing structured text in one platform does not guarantee the same code will work in a different platform.