For Lightning Cat XR2 we naturally developed our own software and related transmission protocols.


In respect of the OSI model, the following diagram shows the layers of the Lightning Cat XR2 protocols:

Physical layer:

In opposite to other systems, the physical layer is not defined very closely.
On the one hand, data transmission between controllers and the MCP-computer is based on RS232C or RS422. On the other hand, transmission between the MCP-computer and the "Remote Control Center" is based on a WLAN-IP-UDP-protocol stack or other radio transceivers.
Herewith, "physical layer" is a loose description.

Link layer:

This layer guarantees data integrity and authenticity.
Between controller and MCP-computer this functionality is limited to a simple checksum algorithm
For data transmissions over Wireless LAN we use relatively secure methods. For example:

  • HMAC (keyed-hash message authentication code) to ensure authenticity of commands
  • Sequence numbers and timestamps to ensure the right transmission order and to avoid replay attacks

The implementation of the link layer depends on the used transmission method on the physical layer and is located in so-called transports.

Network layer:

This layer is responsible for dynamic allocation of addresses to controllers and the routing of commands/responses between all components.

Application layer:

Beside fixed system functions, that all controllers must support, each controller naturally implements its own functions to enable access to its special tasks.

Because of this architecture, it doesn't matter if a real hardware controller (i.e. switchboard) or a virtual software controller (i.e. watchdog) is controlled. This means that all comands are identically and transparently processed.

Remote Control Center (RCC)

The Remote Controller Center (RCC) is used to remotely control Lightning Cat XR2.

It shows all relevant telemetry data (cp. screenshot on the right side):

  • Geographical position inclusive cruise speed (GPS receiver inside car)
  • Position of gas pedal, brake pedal and steering wheel
  • Status of direction indicators, lights, horn etc

Controlling Lightning Cat XR2 is possible with a keyboard, but also with all DirectX compatible input devices (joysticks, gamepads, steering wheels). Button and axes functions can be configured to match the personal preferences of the driver.

We primarily developed a Windows version of the RCC. Adaption to other architectures (i.e. PDA) is easily possible because of the strict seperation between screen display, input- and communication subsystem.