# CommBusAircraft<no value>
The `CommBusAircraft` aircraft is a preset of the [WASMAircraft](../wasmaircraft/) **modular aircraft**, which shows the use of the WebAssembly and JavaScript [Communication API](../../../../programming-apis/wasm/communication-api/communication-api/). Once the {{< glossterm >}}wasm{{< /glossterm >}} Aircraft package has been built, this module will be available for flying from the aircraft selection screen:

{{< image-center
    src="images/7_Samples_Tutorials/Samples/WASMAircraft/CommBusAircraft/commbus_1_aircraft.png"
    alt="Selecting The CommBus Aircraft In The Simulation" >}}

 

The `WasmModules.sln` file (found in the `Sources` folder of the project) will allow you to compile the source-code with Microsoft Visual Studio (2019 or 2022) in order to create the `CommBusModule.wasm` WebAssembly module which will then be loaded by the simulation. Once compiled, the module will automatically be copied into the following folder

\[ROOT\]\(PackageSources\)SimObjects\(Airplanes\)MyCompany\_Wasm\_Aircraft\(presets\)mycompany\(CommBusAircraft\)panel

 

Note that if you make changes to the C++ code and recompile the CommBus WASM module, you will have to build your package again. This *can* be done while the plane is used within the simulation.

 

 

### Testing

Once you have built the aircraft and selected it, you can go into a **Free Flight** and you will see three panels in the cockpit that illustrate the communication between {{< glossterm >}}wasm{{< /glossterm >}} and JS gauges:

{{< image-center
    src="images/7_Samples_Tutorials/Samples/WASMAircraft/CommBusAircraft/commbus_2_screens.png"
    alt="CommBus Aircraft Gauges" >}}

 

Screens 1 and 2 are WebAssembly module ({{< glossterm >}}wasm{{< /glossterm >}}) gauges, while screen 3 is a JavaScript gauge. The top of each gauge has a value, which can be changed using the arrow buttons, and this value will be transmitted to the different gauges depending on:

-   Whether the gauge is registering events.
-   Whether the gauge is applicable to the event being sent.

 

For example, if you click on the `Send To Wasm` button on Gauge 1, then Gauge 2 will display the following message:

<img src="images/7_Samples_Tutorials/Samples/WASMAircraft/CommBusAircraft/commbus_3_wasm.png" class="center" />

 

You can see that the gauge has recieved information - the value set - from the WASM 1 gauge. Likewise, if you click the `Send To JS` button then a similar message will be shown on the JS Gauge screen. Likewise, you can send information from the JavaScript gauge to *both* the WASM gauges using the `Send To WASM` button, and both gauges will show this information:

<img src="images/7_Samples_Tutorials/Samples/WASMAircraft/CommBusAircraft/commbus_4_jswasm.png" class="center" />

 

All of the gauges can be switched to *not* register any events using the register/unregister buttons. If we unregister the gauge WASM 2 and then send a new event from the JS gauge, you can see that only WASM 1 will receive this value:

<img src="images/7_Samples_Tutorials/Samples/WASMAircraft/CommBusAircraft/commbus_5_deregister.png" class="center" />