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I've been working on a plugin which reads datarefs from x-plane and sends them through the ethernet to my home cockpit and then receives some data (like altimeter setting or transponder mode/id) from the cockpit and sends them back to x-plane. The plugin works fine, however it looks like some datarefs, which are described as writeable on, are not really writeable, or at least, writing a value to them has no effect.


- when transponder mode is changed, writing that value (0,1,2,3 or 4) to sim/cockpit/radios/transponder_mode or sim/cockpit2/radios/actuators/transponder_mode has no effect. Have to use XPLMCommandOnce(XPLMFindCommand("sim/transponder/transponder_on")) style command, which works ok.

- same thing with transponder ident button, sim/cockpit2/radios/indicators/transponder_id.

- writing, a float value to sim/cockpit/radios/transponder_code sets the transponder code without any problems, same with the altimeter setting value to sim/cockpit2/gauges/actuators/barometer_setting_in_hg_pilot does the trick.

Also, whenever I use the XPLMCommandOnce function, I can clearly hear a 'double click' sound, which is not there when writing to datarefs, only when executing commands with XPLMCommandOnce.


Would you, please, make those (and probably many more) 'writeable' datarefs really writeable? That would eliminate the need of using XPLMCommandOnce. Also, please advise on that click sound when executing commands with XPLMCommandOnce. It is really annoying.

Have tested my plugin on XP11.11 and 11.20vr1, both the same.

With regards to your hard and awesome work,


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