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Accelerate the tuning and certification of your Electronic Control Unit (ECU)

The development of airborne hardware and software requires thorough verification. Controllers in modern aircraft are upgraded regularly after the initial entry into service.

Bypassing is based on the concept of Rapid Control Prototyping (RCP) by emulating a controller using a real-time target machine and a Simulink® model of the control algorithm. During bypassing, the controller is integrated into the test setup while only certain functions or variables are changed and influenced by the real-time target machine. This saves time since the code for the controller does not have to be completely rewritten.

Controller code partitioning is required to perform bypassing. After this initial effort, testing new functions, parameter tuning, and certification efforts can be executed more efficiently.

Bypassing allows reading and writing the controller's variables without the need for signal conditioning, which may be required in RCP or Hardware-in-the-Loop (HIL) setups.

Depending on the specific application and controller, there are several ways to perform bypassing. One way is to use bypass hooks or service calls to jump from the controller to the real-time system. Another method is to change values in the RAM to overwrite specific outputs of the functions.

"Bypassing will accelerate the development and certification process of your flight controller significantly"

Yves Gerster, Aerospace Industry Manager, Speedgoat

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Featured Application Use Cases

Function-in-the-Loop (FIL)

You can test a specific ECU function by calling the function and reading out the output directly using your real-time target system without performing costly signal conditioning to set up a complete HIL system. This allows you to test single functions on your electronic flight controller or full authority digital controller (FADEC) without accessing the whole system.


Frequently Used I/O Interfaces

Simulink Application Resources 




You can calibrate the controller by directly accessing its RAM and store the calibration parameters, which match the required precision. During extensive testing, parameters in the RAM can be checked regularly to evaluate the robustness and the possible need for recalibration.


Frequently Used I/O Interfaces

Simulink Application Resources 

On-Target bypassing

For electronic controllers with enough ROM and RAM resources, on-target bypassing is an efficient method to tune the controller and test new functions directly on the controller. This reduces the costs for additional hardware and eliminates possible issues arising from potential communication latencies.


Frequently Used I/O Interfaces

Simulink Application Resources 


Configuration Proposal

Real-Time Simulation and Testing

See how it works, learn more about Rapid Control Prototyping and Hardware-in-the-Loop simulation,
to design control designs and test controller hardware.


Request a Configuration Proposal

Get a proposal for a real-time target
machine configured to your needs.

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Curious how to accelerate control design
innovation with a modular controller hardware setup?

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Have Questions?

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about your application requirements.

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