No one on the forum will be able to provide you with any, I believe.
You need to talk to the people supplying the GC, and ASK THEM what data they are mapping to what registers.
You'll also have to figure out how to connect their Modbus RTU to whatever kind of PLC / HMI you have (you never told us, not that it much matters). You should be able to use Google to find ways for your specific type of PLC to Modbus (pretty much they all are capable), and how to physically wire up the module. Modbus IP (if the GC is capable of it) would be a better choice: ethernet is easier to deal with than RS-485. But again, it doesn't matter much.
Even if you can't find something like a ProSoft module for your PLC, there's always a Red Lion DSP protocol converter.
You'll either need very clear manuals (do those exist?), or time to experiment with connecting your PLC to their GC (preferably before FAT, if it's going to be end-user witnessed), just to make sure you're translating their registers right, AND that they're putting the right data in the right format in the right registers.
When I did this a year ago, it took 2 days working with the GC tech to get everything right. (Granted, the GCs were on the top of a 15-story LNG tank - so some of that time was just spent going up and down a lot of stairs, including breaks, forgotten tools, etc. Better him than me....)
Talk to the GC people. That's my best advice. THEY may even have some canned code that has been used on other projects. But don't be disappointed if they don't, or don't share. We all have our proprietary secrets.
