I have had a look around for this stuff but not found the answer so I need to ask the font of knowledge that is here. As is well reported, many of the control codes (66**** etc) that were in FSX/SimConnect don’t work in MSFS. It seems to be the ones that do not come up as an event on the FSUIPC log when clicked in the cockpit.
I have also found that MobiFlight seems to manage to talk directly using Event IDs and can do some of this stuff, which is awesome and I intend to go down that route at some point but am not using Arduino at the moment. Is there a way to get FSUIPC to use Event IDs?
Hmm, problem with that is my cockpit is already built, works fine with FSX, X-Plane, DCS, IL2 etc etc and I would prefer to not rip it apart and rewire everything to make one other Sim work.
Just a hint That Tutorial helps to understand, what kind of offsets in MSFS are reachable for ‚Cockpitbuilders‘ like us and how we can take use of them.
It all works!!! The GNS 530 now does what it is told from my cockpit! Thanks for the info. I now need to give John Dowson some praise and donate to Mobiflight. Thanks again Guit3000
Another question on the same vain. I have just bought the DC-6 and it is amazing. Not a DC-3 unfortunately but awesome just the same. I have the same issue with the DC-6 Gyro-pilot as I did with MSFS G530 etc. I don’t know the event IDs that will talk to the gyro-pilot. I found this here somewhere:
Not sure what to do with it so I tried a new event list in FSUIPC
Mobiflight.DC_6_AP_ON etc
It appears in the FSUIPC lists and I can assign it but it doesn’t do anything. It was just a punt and didn’t expect it to.
That Tutorial helps to understand, what kind of offsets in MSFS are reachable for ‚Cockpitbuilders‘ like us and how we can take use of them. 
