I apologize if this has been asked before, but I've been reading through threads this afternoon and I haven't been able to find an answer.  I am working on designing my transponder and ADF radios. The transponder needs a total of 7 digits to display XPDR_FL and XPDR_Code, while the ADF requires 8 digits for ADF1_Active and ADF1_Standby.

It would reduce the complexity of my design if I could display two values on the same 7-segment display.  For example, using a 8 digit display showing ADF1_Active on the left 4 digits and ADF1_Standby on the right 4 digits.  This would reduce the complexity by reducing the number of 7219 drivers and  multiplexers required for my design.  Is this possible?


May 4 in Output - Displays by

1 Answer

Hi Mike,

You can assign more than one parameter to the same display. When assigning the 2nd parameter, click "New entry" after selecting the display, and enter a position shift value in the options window (by how many digits the value will be shifted to the left side of the screen).

Note that ADF parameters are not fully implemented yet, we're currently working on them.

- Roman
May 4 by


When you select the transponder type KT-70  it shows the flight level in certain modes, accordingly with this device manual.

Namely, when the mode switch is the position ALT or GND it shows the flight level.

So, you need to add the transponder rotary switch to your configuration (XPDR_Mode   parameter).
Just  select and assign all needed parameters in the related image map and all will be working as needed.

As example you can select another model - KT-73, that works fully accordingly with it's tech guide.
All you need is assigning the XPDR_Code, and this universl display will show either code, or flight ID, modes and FL.

You can see how each device should work on this page: https://simvim.com/svc_custom_radio.html

(click the transponder picture).

P.S. If you need to display the flight level constantly in your "no-type" device you can use another parameter (in the Instruments section):
Flight_Level     (but it's not formatted yet as "015"  or as "FL015" )


Hi Vlad,

You are correct, I was not using a SimVim control to select the mode.  Instead, I was clicking the ALT button on the transponder inside of X-Plane.  I assigned a button to XPDR_Mode_ALT, and XPDR_FL started showing on the 7-segment display.

I'm working on building a KT76 replica, however I'm planning on using an encoder instead of rotary switch for selecting the mode.  The encoder will have led's around it to indicate the current mode.  There was a video about using an encoder for a single knob XPDR mode switch, but I think this has been taken down since you are reworking this code.  Will there be a new way to cycle through the XPDR modes with an encoder?  Would you recommend that I use a generic transponder type for this, or the KT76 type?


Hi Mike,

May I ask, why not just use a small rotary switch? If size is an issue, you can use a binary-coded rotary switch - it is small, uses only 3 pins for all positions, and you won't need to use more pins for LED indication.

Right now, an encoder can't be properly used for just any custom mode selector. It may be used if all modes are switched in the right order (0-1-2-3...), but an encoder won't do it if the mode order is different.

Also, you can use one single button to switch the mode (a button will switch them in the required order).

The configurator image maps for transponders are updated.
Now, additional  (or alternate) options can be assigned independently on the selected transponder type.

Hi Roman,

Yes, size was the primary issue, but I was also being lazy since I already had the dimensions sorted out for the encoder.  I did not realize that BCD switches are smaller than rotary switches, so I'll take a look and see if I can make one work.

I had given the switching order some thought, so I was expecting that might be an issue.  Thanks for confirming this for me; I had planned to test it out this week.  I'll test out a single mode button too and decide whether the BCD is worth the effort.