Just went to the Yahoo to search to make sure and it just so happens Peter is discussing this at this very moment, heres what he is saying
"Hi Andy,
Wether the MPG is coming from a ModIO or MP-01 pendant, the Modbus data
entering Mach3 is identical.
The only difference I can see is that using the legacy Modbus serial
interface produces smooth movement, whereas using the new Plugin support
Serial interface does not.
In the early days, Art and I had a lot of correspondence to get the MPG
smooth in the Legacy serial Modbus interface.
I have asked Brian a couple of times to look at the MPG issue that Mach3
now has. I even sent him a ModIO to test with.
As I understand it, Brian is too busy with other issues, so fixing the MPG
issues is lower on the list.
If there was anything that I could do from my end, I would. If Brian needs
anything from me, I'm happy to provide it.
It's a bit of a shame that Modbus does not bet a higher priority,
considering it is probably the most widely used communications protocol in
industrial control."