systems.cfg

The systems.cfg is an optional file for SimObjects, unless you are creating an aircraft in which case it is mandatory. This file is used for defining various different aircraft systems. Below you can find information on the different sections used in the systems.cfg file as well as what parameters and values are expected within them.

[Version]#

The [Version] section provides version information for the configuration file. In Microsoft Flight Simulator 2024, major versions should always be at least equal to 1.

Note that this section information is mandatory and should always be included.

[BRAKES]#

This section controls the aircraft’s brake systems. Available parameters are:

[GEAR_WARNING_SYSTEM]#

This section defines the functionality of the gear warning system for the aircraft. This is generally related to the throttle lever position and the flap deflection. Available parameters are:

[LIGHTS]#

This section controls the lights on the aircraft. The given index value can then be passed to the corresponding light SimVar to apply a different behavior to different lights. Note that there is an additional option in The SimObject Editor to enable/disable the light in the simulation for testing, but this option is not included in the associated CFG file: Turn Light On / Off. This option will only work if is enabled:

Available parameters are:

The hash map that each light takes is comprised of the following key:value pairs, separated by the # symbol:

Below you can see an example of a light definition:

lightdef.18 = Name:light_strobe Type:4 #Index:0 #LocalPosition:-1.2,0.65,14.0 #LocalRotation:0,0,0 #EffectFile:fx_cockpit_small_yellow, #PotentiometerIndex:2

It is worth noting that we have a page giving an overview of how lights should be setup from the following link:

• Implementing Lights

Legacy Lights#

When working with legacy aircraft from before MSFS 2020 (for example) you will find that lights were defined slightly differently. Here we explain the format used for those lights, but for new aircraft you should be using the lightdef.N parameter.

Legacy lights are defined using the following parameter:

The table for these lights takes 8 entries, listed below:

When writing out a light definition, you may specify a node on the aircraft model instead of the (z/x/y) position, and omit or include the rotation parameters depending on requirements. Below are examples of various combinations of data you can use to define a light:

; light.n = CircuitType, NODE_HELPER_NAME, fxfile
light.0 = 3, light_navigation_node, fx_navred

; light.n = CircuitType, ZOffset, XOffset, YOffset, XRotationInDegrees, YRotationInDegrees, ZRotationInDegrees, fxfile
light.0 = 3, -2.6, -17.4, 3.6, 90.0, 0.0, 0.0, fx_navred

; light.n = CircuitType, NODE_HELPER_NAME, XRotationInDegrees, YRotationInDegrees, ZRotationInDegrees, fxfile
light.0 = 3, light_navigation_node, 90.0, 0.0, 0.0, fx_navred

[NIGHT_VISION]#

This section defines whether the aircraft pilot has access to night vision goggles or not when flying the aircraft. The available parameters are as follows:

[ELECTRICAL]#

This section controls everything related to the aircraft electrical systems. The electrical system is modular in nature and is based on a combination of component, configuration, and connection parameters. This section also has the following parameters that can be used to select a specific version of the system to be used, and requires both the major and minor values to be set, eg:

[ELECTRICAL]
Major=2
Minor=1

An electrical system is defined by its main components, of which there are multiple types:

To help with the configuration of the components you have configuration items:

Finally you have the connection components:

[HYDRAULIC_SYSTEM]#

This section controls the hydraulic pressure systems.

Available parameters are:

[HYDRAULICS_SYSTEM_EX1]#

This section controls everything related to the aircraft hydraulics system. The hydraulics system is modular in nature and is based on a combination of components, that are connected by lines, and each line can have special line features.

Apart from components and line features, you also have the following parameter that is used to tell the simulation which version of the hydraulics system is being used:

A hydraulic system is defined by its main components, of which there are multiple types:

Additionally, you can add the following line features to the system lines:

Each of the components listed above can be defined multiple times as parameters within the [HYDRAULICS_SYSTEM_EX1] configuration header. You can find more information on setting up the hydraulics system form the following page:

• Hydraulics System Setup Information

And you can find examples of use here:

• Hydraulic System Examples

[PNEUMATIC_SYSTEM]#

This section controls the pneumatic system of the aircraft.

[PNEUMATIC_SYSTEM_EX1]#

This section controls everything related to the aircraft pneumatic systems.

Apart from components and line features, you also have the following parameters:

A pneumatic system is defined by its main components, of which there are multiple types:

Additionally, you can add the following line features to the system lines:

[VACUUM_SYSTEM]#

This section controls the aircraft vacuum system. Vacuum system suction is controlled by the [PNEUMATIC_SYSTEM_EX1] section, specifically the Outlet.N hash map.

Available parameters are:

[PITOT_STATIC]#

A pitot-static system is a system of pressure-sensitive instruments that is most often used in aviation to determine an aircraft’s airspeed, Mach number, altitude, and altitude trend. This section permits you to set certain attributes for using this system. Available parameters are:

[STALL_WARNING]#

This section controls the stall warning system. Available parameters are:

[DEICE_SYSTEM]#

This section controls the de-ice system. Available parameters are:

[RADIOS]#

This section controls the aircraft radios. Note all systems listed here start at N = 1, and the available parameters are:

[AUTOPILOT]#

This section controls the aircraft autopilot systems for both planes and helicopters.

The available parameters for planes are:

The parameters available to helicopters are:

[SMOKESYSTEM]#

This section controls the aircraft smoke system. Available parameter is:

[folding_wings]#

If the aircraft being defined has folding wings, this section should be included. Available parameters are:

[TailHook]#

This section controls the tailhook of the aircraft (if required). Available parameters are:

[launch_assistance]#

This section controls the launchbar (assisted takeoff) parameters for an aircraft that requires them. Available parameters are:

[VOICEALERTS]#

This section controls any voice alerts for the aircraft. Available parameters are:

[PRESSURIZATION]#

This section controls the cabin pressurization systems. Available parameters are:

[AUXILIARY POWER UNIT]#

This section controls APU systems. Available parameters are:

[WATER BALLAST SYSTEM]#

This section controls the water balance system. Available parameters are:

[Liquid Dropping System]#

This section controls everything related to the aircraft Liquid Dropping System. This is a modular system that is made up from various connected components. The available components and parameters are as follows:

[Burner_System]#

This section controls the burner system used by hot balloon sim objects. Available parameters are:

[LocalVars]#

This section can be used to set the initial value of persistent local variables to be used in the XML Model Behaviours templates and gauges. These local vars are accessed using the “L:” var identifier in Reverse Polish Notation, and if you are using the JavaScript API then it’s done the same way as for SimVars, using the GetSimVarValue(name, unit, dataSource = "") function. These variables are shared between aircraft if multiple instances of the aircraft are spawned. In general this is not what you want and you should use the scoped L:1 variable type instead, defined in the [LocalVars_EX1] section.

When an aircraft is selected by a user and the flight is first started, these “L:” vars are defined using the LocalVar.N parameter and then initialised using a default value (done using the LocalVarDefault.N parameter). Any changes to these variables that have been made will then be saved to a file (state.cfg) when the flight is exited. This file will be saved to a local location on the users computer using the following path schema:

• STEAM: C:\Users\<USERNAME>\AppData\Roaming\Microsoft Flight Simulator\SimObjects\<AIRCRAFT_NAME>\state.cfg

• MS STORE: C:\Users\<USERNAME>\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\SimObjects\<AIRCRAFT_NAME>\state.cfg

The next time the aircraft is used, the local variables will be initialised as before, only now they will be set to the values stored in the state.cfg.

Note that if you define a variable here but don’t initialise it with a default value, then the first time it is used it will be considered as having a value of 0.

[LocalVars_EX1]#

This section can be used to set the initial value of persistent local variables to be used in the XML Model Behaviours templates and gauges. These local vars are accessed using the “L:1” var identifier in Reverse Polish Notation, and if you are using the JavaScript API then it’s done the same way as for SimVars, using the GetSimVarValue(name, unit, dataSource = "") function. These variables are scoped to each instance of the aircraft that use them, so each instance will have a unique version of the local variables you define in this section (unlike the un-scoped L var type defined in the [LocalVars.N] section).

When an aircraft is selected by a user and the flight is first started, these “L:1” vars are defined using the LocalVar.N parameter and then initialised using a default value (done using the LocalVarDefault.N parameter). Any changes to these variables that have been made will then be saved to a file (state.cfg) when the flight is exited. This file will be saved to a local location on the users computer using the following path schema:

• STEAM: C:\Users\<USERNAME>\AppData\Roaming\Microsoft Flight Simulator\SimObjects\<AIRCRAFT_NAME>\state.cfg

• MS STORE: C:\Users\<USERNAME>\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\SimObjects\<AIRCRAFT_NAME>\state.cfg

The next time the aircraft is used, the local variables will be initialised as before, only now they will be set to the values stored in the state.cfg.

Note that if you define a variable here but don’t initialise it with a default value, then the first time it is used it will be considered as having a value of 0.

[WASM_SYSTEM.N]#

This section is used to set up a reference to a WASM system module. This is an indexed section, with the indices starting at 0 and going up by 1 in consecutive order. Each indexed section is used to setup a single WASM system, and has the following parameters:

For more information on WASM System modules, please see the following page:

• Creating WASM Systems