Im a little confused on how to wire up the red and yellow LED on AP Disco Alert and AT Off control since on the configurator there is only one output for the Boeing 737 MIP. Thank you
May 22 in LEDs, Digital Output by

2 Answers


Yes, currently there is only one output (for one LED).

You can take the "TEST" switch (3-position switch at the right of these lights) with additional contact group (the DPDT switch).
Use these contacts to switch power between internal red or amber LEDs (amber - in upper switch position).
This is related to one of the functions of this "amber light":  "Illuminates (amber) when test switch is held to position 1"  because other functions seems not implemented - neither in Laminar default B737, nor in Zibo mod.
So, it doesn't make sense to have these amber lights, or it makes sense when someone needs all indications  just to be in place.

Note, that even in some of the most "real" commercial plane models, if you see all LEDs lightened at test and switches flipping, that doesn't mean that the systems are really working (and not all of them are needed in the simulator of course, such as "seat belts light", etc.)

I know  that Zibo has datarefs related to these lights (to see them onscreen),  but I don't see they work in certain conditions.
For example when   AP switches  from CMD to CWS or  any airspeed error conditions when A/T on and flaps are extended.

For these AFDS panel we can add functions to the SimVim program (such as "When flaps are extended" and "Desired airspeed is not reached"  for A/T, etc., and it will work independently of the custom model.)


May 22 by
Thanks for adding them! Is it possible to use the separate datarefs that are availabe for pilot and copilot, including the test switches? I think those are pretty much Zibo-specific anyways, so it wouldn't cause trouble with other aircraft.

I am not a commercial pilot, but an enthusiast building a full-size B737 Homecockpit, based on Zibo. I have done a lot of research and found this missing feature when I wired up my AFDS panel and noticed it not being in sync with the Zibo.

"..full-size B737 Homecockpit, based on Zibo.. "

I always try to explain this to the people who started their home cockpit project:

1) Forget about any specific virtual airplane model (developer) before building!

That's mean, If you want b737 - build a real b737, not Laminar (or Zibo-mod Laminar), not FlightFactor, etc.  You take all the necessary documents, photos and build all the necessary panels, switches, displays.

Later you can always choose (or change) any virtual model for the flight.
As you see, in opposite to other previous interfaces,  SimVim uses unified naming for every aircraft function, and you don't have to stick to any virtual model.

So, all you need - is building a replica of the real plane panels and assign all needed controls and displays.

2) Since this is your home simulator, and you do not plan to become a real Boeing pilot, do not take it too seriously,  you will never have a chance to land  an airplane with unconscious pilots :).

  • - It is obvious that not all the controls and annunciators that you can find in a real airplane need to be active in your cockpit! Think first: why you really need it? Do not waste your time, money and efforts trying to replicate unnecessary (in a home cockpit simulator) switches and lights.

    Even if these controls are implemented in the virtual plane model you use, many of them are just “dummy”, used by the developer for visual representation and not bearing any real functionality. Moreover, it’s just “weird” to have some annunciators and switches implemented in your home cockpit (like the "occupied toilet" lamp :).

  • - For the LEDs that only have the purpose of indicating a switch position (toggle, push putton or rotary swicth) you don't need to use any output parameters, you need to use the switch that have additional contact groups to directly connect the LED indicating the switch position (example - most of the korry-type switches in Airbus overhead panel).

3) As you may know, I don't like current developers practice to put their own datarefs to every simple or even dummy functional knob, switch , etc, just to provide animation.

I see that  90% (minimum) of all functionality in any custom plane can be made using only default XP commands.  Only a few custom system "logic" needs to be programmed in some planes. 

And there are  mistakes, wrong logic always appeared in custom planes, or custom "mods".

For example, the Bleed Air panel is working correctly in the default Laminar B737, accordingly with all new XP11 additions, including the pressure gauge, packs.

In contrast, the popular  "zibo" mod for Laminar b737 has wrong (at least in the current version, I suppose) bleed panel behaviour, for instance, you can not use the cross-side engine start, only from APU bleed available, and the starter switch return works not as real.

The SimVim starter switch return function (as many others) works not using any custom (and Zibo) datarefs, and have realistic logic.

Good luck,


In new updated Autopilot section in the configurator you can assign these  lights.
AFDS WARN and  AT warning lights.

Jul 19 by
Thanks! I couldn't test them all yet, however I noticed when moving the test switch to the 2-position, both the amber and red LEDs turn on. In position 1 only the red LEDs turn on correctly.
Thanks Vlad for the updated AFDS WARN and AT warning lights.

I also tested the new functions on my 737-HomeSim. Configured the AFDS test switch to "AT_Off_Test" and "AP_Off_Test", as shown in the Boeing 737x MAP. Next I configured  "AP_Disco_Alert" / "AT_Off_Control" to red LEDs  and "AP_Warning" / "AT_Warning" to amber LEDs. Unfortuanetly I got the same result as described by AndyKrause. What are we doing wrong?


Bernie Neuhausen