Scratch the last post .. I could not get the ModIO to communicate with the drive no matter what I did.  It's working with the RS232/RS485 converter & I can Start/Stop/Change Direction/Change Frequency from the Modbus Test page in Mach .. what I can't seem to do is come up with a brain that will either change directions or frequency using the MDI.  As far as changing direction .. the motor pauses but continues on in the same direction .. or the VFD faults.  With frequency control I'm having NO luck at all!

Any help would be appreciated

Well after MANY, MANY headaches .. It's working!
Scratched the ModIO & used a 232 to 485 converter and I have control over fwd / rev & speed ..
Will post some screen shots of my final setup when I can get back to this .. right now I'm DONE!

This thread is now dead .. I added a new thread called 'My SJ200 & Mach3 setup' to avoid confusion