UniversRadio Transponder

Summary :

1- When to use UniversRadio Transponder?

UniversRadio Transponder (UR IFF) is a virtual MODE1, MODE3 and MODE4 transponder and Identification Friend or Foe.
It is designed for DCS:FC3 NOTA fighter aircraft. So the F-15C…
UR IFF is not needed for A-10C, C-101EB, F-5E3, M2000C, UH-1H and F-14B, in-game cockpit panel settings are taken.


An IFF interrogation works only during a radar locked on, and from FC3 flighters.
/!\ Make sure than the DCS server allows objet export /!\ (see advanced server setting)

With UR Transponder :

  • pilots set transponder according to the breifing and/or ATC,
  • a human fighter pilot can do an IFF interrogation (interrogation must be done during a radar locked on),
  • an ATC software (LotATC) can use IFF or Ident status to manage air circulation.

Launch UniversRadio Control Panel from UniversRadio DashBoard shortcut and choice “Transponder” :


2- How to use it ?

You will find UR Transponder shortcut in the Windows start menu UniversRadio.


Which actions can be done ? And, how to do ?

Setting codes
Mode 1 & mode 3
Left mouse, right mouse
or wheel mouse on focused mode
Setting IDENT requestLeft mouse
Setting Standby Left mouse
Setting Mode 4Left mouse on "M4" button
Doing an interrogation
Left mouse button
Joystick (see UR Control Panel)
Keyboard :

Query : [Y]
Display on top or hide UR TransponderLeft mouse on arrow
Keyboard :

[Left Alternate]+[T]
Get and release UR Transponder
as primary Window
/!\ DCS will be not able to
receive any command when
UniversRadio Transponder has focus
Middle mouse button

When UniversRadio Transponder has focus,
frequency is displayed in orange
Moving window 1. Get the focus : middle mouse button
2. Press and hold left mouse button, move cursor
3. On the good position, release left mouse

You can customize an IFF code for AI aircrafts. Add #IFF:xxxxcc at the unit name from DCS mission editor. xxxx is the mode3 code and cc is the coalition : UN (unknown), EN (ennemy) or FR (friendly).


Example for a IA A/C name : PARA_82ND #004 #IFF:1204FR
So, when an interrogation will be done on this A/C, IFF respons will be -- 1204 FR.

You can change IFF keys by modify ..\Saved Games\UniversRadio\UniversRadio.ini file (read included comments). This key is a secret share of your coalition.

3- Screenshot

UR Transponder is setted with
00 mode 1 code
7000 mode 3 code
Mode 4 is off
UR Transponder is setted with
01 mode 1 code
7000 mode 3 code
Mode 4 is off
in standby position
as OFF, it can transmit
UR Transponder is setted with
01 mode 1 code
7000 mode 3 code
Mode 4 is off
with IDENTification position

4- Results of “QUERY” interrogation

An IFF interrogation must be done during a radar locked on.

Result and interpretationQuery window display
IFF, transponder, remote squawk is OFF
or contact is not locked on
Civilian A/C : An-26B, An-30M, IL-76MD or Yak-40
DCS AI A/C have mode 3 codes begining by 6
with IFF code in UR CP is 000
It is a friend military DCS AI A/C
DCS AI A/C have mode 3 codes begining by 4
It is a human A/C
with same IFF code in UR CP
mode 1 code : 01
mode 3 code : 4548
Mode 4 is on2
Mode 4 is on2
It is a human A/C
with a different IFF code in UR CP
It is a ennemy DCS AI A/C

2According to IFF mode 4 ‘Secure Code’ in UniversRadio Control Panel.

5- Interaction with UniversRadio ExternalRadio


When both, UniversRadio ExternalRadio and UniversRadio Transponder are launched, UniversRadio Transponder is displayed below ExternalRadio window.
UniversRadio Transponder window can be moved.

When UniversRadio ExternalRadio has focus, both windows display frequency and code in orange color.