Accessing Fenix A320 radio frequencies via external script (LVARs / HVARs / SimConnect?)

[trayced]

Hi everyone,

I’m currently working on a small external script for the Fenix A320 and I’m trying to control the COM/NAV radio frequencies programmatically — not via a hardware peripheral like the Logitech Radio Panel, but purely through software.

I already contacted Fenix Support, but didn’t receive further information on this, so I thought I’d ask the community:

My question:
Which variables (LVARs, HVARs, or SimConnect events) are used to control the radio frequencies in the Fenix A320?

In other words — is there a way to change the active or standby frequency via script, or to simulate knob rotations on the radio panels externally?

I’m not looking to read data from a device, but to send the relevant variable updates myself (for example, through a Python or C# SimConnect script).

If anyone knows the variable names or how to interact with these radios from outside the sim, I’d really appreciate your help!

Thanks in advance,
trayced

Edited 3 hours ago by trayced
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[John Dowson]

First, I presume this is with using MSFS2020 / MSFS2024, so I have moved it to the appropriate forum.

16 hours ago, trayced said:

Which variables (LVARs, HVARs, or SimConnect events) are used to control the radio frequencies in the Fenix A320?

I don't have the fenix, but looking at the avionics presets in HubHop (https://hubhop.mobiflight.com/presets/?vendor=FenixSim&system=Avionics) it looks like lvars are used for most of the buttons. I don't know if the standard FS controls (Simconnect events)  to set the frequencies will work, but I suspect they would (they work in most aircraft to set the frequencies).

16 hours ago, trayced said:

I’m not looking to read data from a device, but to send the relevant variable updates myself (for example, through a Python or C# SimConnect script).

If anyone knows the variable names or how to interact with these radios from outside the sim, I’d really appreciate your help!

If you don't want to use the SimConnect SDK, you can use one of the FSUIPC SDKs to do this (and the WASM with the WAPI for lvar/hvar access). The C# library is the most advanced and also integrates with the WASM / WAPI- see Paul' Henty's .Net dll client sub-forum: https://forum.simflight.com/forum/167-fsuipc-client-dll-for-net/

A Python wrapper is also available - see the FSUIPC SDK folder (i.e. install FSUIPC7 and look in the SDK folder).

John

[trayced]

Thanks a lot for the detailed reply!

Yes, I’m using MSFS 2020, and I already tried the standard SimConnect events (like COM_RADIO_SET, COM_STBY_RADIO_SET, etc.) — unfortunately, none of them work with the Fenix A320. It seems those are completely disconnected from the internal radio logic.

I also haven’t been able to find any LVARs or HVARs related to the COM/NAV frequencies or the rotary knobs so far, but I’ll take a look at the HubHop database you linked to and see if anything shows up there.

Thanks again for the pointers!

trayced

Edited 3 hours ago by trayced
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[John Dowson]

For COM frequencies, you can use FenixQuartz (https://github.com/Fragtality/FenixQuartz) which provides the lvars  "FNX2PLD_com1Active", "FNX2PLD_com1Standby", "FNX2PLD_com2Active" and "FNX2PLD_com2Standby" - although these may be read-only. This post indicates that these hold the correct values in MSFS2020, but not in MSFS2024: 

The OP of that topic also indicated that he has found a way without using FenixQuartz - I have asked if he can provide any further information on this.

John