MSFS 2020 APU issue

Sorry for my previous reply – I responded to quickly without understanding the question. I have deleted it.
I don’t have the PM-B737, but will take a look at the Asobo 787 when I get a chance, probably tomorrow.

Posted by: @dl4saw

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Is there a “hidden” or not dokumented battery switch?  Any idea?

There is probably another event you need to trigger, The MF preset for the B787-10 start uses the b-var (input event) B:ELECTRICAL_APU_Starter_Set, but this would be for MSFS2024. You cannot use b-vars directly in MSFS2020, but you can use input events – you could see if one is available for the APU in MSFS2020.

You could also maybe see what events are triggered when you start/stop the engines with CTRL+E. This may give a clue as to what additional event needs to be triggered. Otherwise, you can examine how the APU starter switch works using MSFS’ developer tools (behavior window). This may give a clue as to what is needed.  

I will get back to you when I have taken a further look.

John

the main prerequisit to start the APU is switching the main battery. The event is: ELECTRIC_PUSH_BATTERY. Unfortunately I could not find the corresponding variable in FSUIPC. I use FSINTERROGATE, I compared the full area (all known and unknown varialbles) without finding the change. Should I move to other tools to log the events?  Sorry I am new with MSFS-2020, I know that a lot changed.

Posted by: @dl4saw

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The event is: ELECTRIC_PUSH_BATTERY. Unfortunately I could not find the corresponding variable in FSUIPC.

Where do you see this? There is no such event as ELECTRIC_PUSH_BATTERY, and no such simulator variable.
The list of available MSFS events can be found in a text file in your FSUIPC7 documents folder, called ‘Controls List for MSFS Build 110.txt’, and are documented here:

    https://docs.flightsimulator.com/html/Programming_Tools/Event_IDs/Event_IDs.htm

 The simulator variables available in MSFS2020 are documented here:

    https://docs.flightsimulator.com/html/Programming_Tools/SimVars/Simulation_Variables.htm

Note that only a subset of the simulator variables (aka simvars) are actually held in FSUIPC offsets. Please see the FSUIPC7 Offset status document for details on what is held in offsets.

Posted by: @dl4saw

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I use FSINTERROGATE, I compared the full area (all known and unknown variables) without finding the change.

FSInterrogate is very old now and the data files have not been updated to include the additional offsets added for FSUIPC7. Better to use the documentation on offsets.

Posted by: @dl4saw

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Should I move to other tools to log the events?

To log events, you should use FSUIPC7;s logging facilities. Set logging for Events, open the logging console (Log -> Open Console), and you can see what events are generated when you press any button/switch.

For the battery in the Asobo B787-10, there is a toggle preset available (see https://hubhop.mobiflight.com/presets/?vendor=Asobo&aircraft=B787-10&search=batt):

it uses the ELECTRICAL_BUS_TO_BUS_CONNECTION_TOGGLE event.

There are also presets for the APU: APU Switch On, Off & Start. However, these use the B-var ELECTRICAL_APU_Starter_Set, but as far as I am aware you still cannot use b-vars in calculator code in MSFS2020 (you can in MSFS2024), so I can’t see how these presets can work. Maybe worth trying though, just in case.

 However, there is an Input Events (which maps to the B-var): ELECTRICAL_APU_Starter. You could use that, with values:
    0 – Off
    1 – On
    2 – Start

Just tried that here, and setting this Input Event to 2 turns the APU switch to Start, and then it goes back to On.

There is also an Input Event for the battery: ELECTRICAL_Battery_Switch. You can set that to 1 / 0 to switch the battery On / Off.

You can also use logging to list available Input Events (Log -> List Input events) and also see what Input Events are being triggered in real time (Log -> Input Events).

I done have the PM-B737. You will need to use logging to see how it works in that aircraft.
If all else fails and logging doesn’t reveal anything, you can use the MSFS developer tools to see how the switch is implemented. See the following article (N.B. you don’t need to use MobiFlight – use this to determine what the switch is using and then replicate that in your FSUIPC7 assignments, either using a preset or something else): https://www.badcasserole.com/uncovering-input-events-using-the-msfs2020-model-behavior-dialog/

John

Also, if you are writing to offsets to control things rather than assignments in FSUIPC, you can use offset area starting at 0x7C50 to set Input Events, call presets, set lvars and execute calculator code. See the FSUIPC7 Offset Status document for details.

John