I've been using your product for a while now, and today I was surprised to find that neither of the two 750s on board were working at first. After reading the forum, I restarted my computer and now only one is working. For your information, I'm flying with the Torquesim Citation for X-Plane 12.
Thank you for your help.
Hello,
Can you please check for electrical power, as the GTNXi units are tied to different electrical sources. This you can always adjust to "Always on' as a test, via the Plugins menu\TDS GTNXi Unit 1/2 /Settings, as described in the TDS GTNXI XPlane PDF manual.
A different test for the dual GTNXi config (750Xi + 650Xi) in the default C172 with the TDS GTNXi integration:
https://forums.x-plane.org/files/file/94...ompatible/
I can't access the settings for the second GTN750. I also have the XP Reality, which works fine on both units. Between two restarts of X-Plane, without me touching anything, the second unit stopped working. I can't even get a log for Unit 2.
ok I re isntall the Torquesim Citation and now it's working fine... that is strange but it's solved

Hello,
Thank you for letting us know. We strongly recommend uninstalling other third party GTN GPS units as they will cause conflicts, when running the TDS GTNXi XPlane.