Has anyone else tried to do this? Any luck? I can't get a valid response from the SG2 even using tools like ModScan32 and ModTester. I've tried termination resistors, swapping polarity, and jumping the Rx and Tx together on the 4wire adapter (Hexin 2108G). The only thing that changed with each of these was no response from the SG2 instead of an invalid one.
I really like the SG2 for simple projects, but if I can't get it to talk to a PC it really limits it's usefulness.
Sounds like you are in the same boat I was. I even purchased two of the units in an effort to get it working. Don't get me wrong - I REALLY like most of factorymation's products - I use their VFD's with Modbus and they work GREAT! But the Teco SG2 is junk when it comes to Modbus.