cnc machines issues and software upgrade

[iain1mm]

I work for a university engineering dept. and would strongly recommend keeping these machines off the school network if you can. There should be no need for them to connect to the outside world and externally generated files can be uploaded to them via usb memory sticks.
I now have my main pc at work connected via a wifi dongle (i.e.can't do any more harm than someone with a smartphone) and have a small Ethernet switch network set up for my four cnc machines. This has been a HUGE benefit to getting things done and I am not constantly plagued with network updates.
Staying off the main network has been helpful with cad software updates and plugins as well as I can pretty much do what I like :) It is like working from home at work!
Not sure on your datum issues but if left to my own devices I would rewire everything with AXBB motion controllers, and run uccnc software. It is very similar to Mach3 but is well supported and WAY more reliable than my 4 years of mach 3 shenanigans would suggest.
I wish I had time to come and help but the only reason I have had time to even answer this is because I am sat at home with covid!
Standalone machines should not present a risk to school security. If your IT dept are really windy about the risk of accidental connection to their impeccably guarded network (that no doubt, is our last defence against the new axis of evil) then get them to disable / remove the ethernet adaptor (possibly by stuffing stuffing chewing gum in the connector hole)
The datum thing will likely be a limit switch wiring issue or a Mach 3 setting issue. Both should respond to 30 mins max of sheer bloody mindedness :)