From the main Mach4 screen, go to the "Configure" menu and select "Mach...". Then click on the "Input Signals" tab. If you have a PMDX-422 or PMDX-410 and it is plugged into the PC and our plug-in is able to talk to it, then the A, B and C inputs should show up as "PinA", "PinB" and "PinC" in the drop-down list in "Input Name" column for any signal that has "SmartBOBUSB" selected in the "Device" column. You should see "Pin10", "Pin11", "Pin12", "Pin13", "Pin15", "PinA", "PinB" and "PinC".
If you don't see them listed then all I can guess is that the plug-in thinks you have a PMDX-411 instead of a 410 or 422. Go to the "Diagnostics" menu and select "PMDX-SmartBOB-USB". That will show you what the plug-in thinks is connected to the PC. You can also create a profile package and send it to me (either upload it here or email it to me at "bob" at this domain). To create the profile package, go to the Mach4 "Help" menu and select "Support" and then "Create Profile Package". Save the file somewhere that you can find it, then upload or email it.
Bob