TSIP is an engineers dream, very over complicated. Not all TSIP is the same the guidance dictates the connection requirements.
This converter is snapped up by agra-gps, so I cannot divulge too much on its code.
All the documents you need can be downloaded directly from Trimble Website, they have a TSIP Manual and a suite of TSIP reference material available free of charge. Also found more info by reading their manuals unrelated to the ag receiver.
Its not a direct 1:1 data conversion from UBX to TSIP, much transformation of the data is required.
I started coding C in October, started the version for 250/500 in January. Hopefully will be fully vetted and released by next year.
I now have a Topcon unit in a combine available to me, so that is the next receiver to decode.