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FSX:SE What drives the A:CIRCUIT GENERAL PANEL ON variable value?

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BlueSox14

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australia
Hi there,

I'm relatively new to poking around the insides of FSX. I've spent a little bit of time over the last number of days reading through the online SDK and poking at the xml gauge files of the default 737-800.

Something that crops up in some of the default 737 gauges is a check on the A:CIRCUIT GENERAL PANEL ON variable. This appears to be a check to see if power is being fed to this particular circuit. I have no problems with that.

What I have learned is that this is a variable that cannot be changed by the user directly. It is non-settable according to the SDK and is what some call an 'internal' variable.

What I'd really like to know is what drives this variable to be either value 0 or 1.

I suspect it has something to do with the [electrical] parameters that can be configured in the aircraft.cfg file as well as the Boolean variables that can be driven by user action (GENERAL_PANEL_CIRCUIT_ON, FLAP_MOTOR_CIRCUIT_ON, MASTER_BATTERY and AVIONICS_MASTER_SWITCH etc).

However, I could be way off the mark. So I'd really appreciate it if someone could shed some light on just how the A:CIRCUIT GENERAL PANEL ON variable works - what is the driver that causes it to change it's value between 1 & 0.

If it's not too much trouble, I'd appreciate the same sort of explanation for the various other A:CIRCUIT variables.

Thank you!

Trent
 
A:CIRCUIT GENERAL PANEL ON will be a one when either :
1) Battery is on and is above minimum voltage stated in the aircraft.cfg
-or-
2) Any engine is running and it's respective generator is on and operating, again above minimum voltage
 
Thanks spokes2112 for your reply.

I found a useful thread from some years ago here: https://www.fsdeveloper.com/forum/threads/of-master-switches.5376/

Contained in this thread is the theory that the battery and all generators power the main bus (bus 0), and therefore every circuit connected to the main bus.

By default all circuits are connected to this main bus.

I assume these are the 13 circuits mentioned in the SDK (https://msdn.microsoft.com/en-us/library/cc526981.aspx): General Panel, Flap Motor, Gear Motor, Autopilot, Avionics etc.

I have some further questions:

1) The SDK provides for 8 Bus Types (0 - 7). See https://msdn.microsoft.com/en-us/library/cc526949.aspx#mozTocId245287. If the Battery powers Bus 0, what powers Bus 1-7?

2) Is it possible to transfer a circuit from main bus 0 to another bus? How would you do that?

With my second question, I suspect the way to do this is to through the [Electrical] section of the aircraft.cfg. The SDK (https://msdn.microsoft.com/en-us/library/cc526949.aspx#mozTocId245287) provides 38 parameters that can be added to the [Electrical] section identifying the Bus for each.

3) Are each of these 38 parameters/systems hardwired in FSX to one of the 13 circuits above?

4) If 4 is true, is a schema or reference available to review this mapping?

I'd appreciate any help with the above. After wading through many threads, I realise the electrical systems in FSX leave a lot to be desired. Nonetheless, this is a learning experience for me and I'm enjoying it.

Thanks everyone,

Trent
 
BlueSox14 said:
After wading through many threads, I realise the electrical systems in FSX leave a lot to be desired.
Click to expand...
That's a bit of an understatement! In truth, your best bet is to drag out the aircraft's FOM or MM and code up the entire electrical system from scratch. That way you have complete control over it and you can make it as accurate as you want. I haven't used the FS default electrical systems in -oh- twenty years... :D
 
BlueSox14 said:
Thanks spokes2112 for your reply.

1) The SDK provides for 8 Bus Types (0 - 7). See https://msdn.microsoft.com/en-us/library/cc526949.aspx#mozTocId245287. If the Battery powers Bus 0, what powers Bus 1-7?
2) Is it possible to transfer a circuit from main bus 0 to another bus? How would you do that?
3) Are each of these 38 parameters/systems hardwired in FSX to one of the 13 circuits above?
4) If 3 is true, is a schema or reference available to review this mapping?

Trent
Click to expand...

#1 Bus #0 can be powered by the battery (if on) or any generator if running. ( A:CIRCUIT GENERAL PANEL ON, bool)
#2 No (w/ 1 exception) - Each bus is essentially diode isolated within the internals of FS. Except... The avionics bus (in .cfg "avionics_bus=") can be sourced by any other bus.
#3 No, you can attach any system (of the "not quite" 38) to any bus.
#4 Attached is a general schematic of what could be done with the built in electrical system. (could be wrong with this but seems "electrically" correct)

scematic.jpg
 
Wowsers! Very impressive.

It's too late at night for me to digest that, so I'll leave it to tomorrow, but thank you for taking the time to do that.

If I have further questions, I'll come back and ask.

From a positive point of view, it's people like you who have taken the time to respond to my questions that has given me enough help with xml coding for me to go ahead and fix a number of irritations within the 2D panels of the default B737-800. The community has taught me a lot in the last fortnight or so. So thank you all!

Tonight I stumbled across the reversed 2D / 3D fuel crossfeed valve knob in the default 737. Aye aye aye! What were Microsoft/Aces thinking? There are so many basic things wrong with this aircraft that should've been picked up in testing I would've thought. Anyhow, I persist in my work of getting this aircraft as right as I can although as I understand it, that's a bug that I just cannot fix.

Maybe I could just 'reverse' the 2D panel knob operations to align?..arrgh. I'll think more about that tomorrow!

Thanks again!

Trent
 
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