Camera hardware has a modular structure (along with high performance). These are the main and most commonly used boards:
The system board has a CPU running Linux and we can use it's universality to implement open code done by others as well as our own in the camera, even the processor is not the most common one – it is Etrax, by Axis. The FPGA (Field Programmable Gate Array) is responsible for image processing and compression.
Interface board is for additional interfaces like SATA, USB or Serial port. It makes possible attaching HDD to the camera to record images on it, and USB external devices like GPS. This board also allows precise external synchronization. It is helpful for software development and troubleshooting, as it provides serial console.
Separate Sensor board allows to use different sensors with the same system board.
With the Multiplexer board up to 3 sensors can be attached to the camera. Attaching 2 sensors makes it a stereo camera, for example.
More FPGA programming can be also done on the Multiplexer board, without compromising the FPGA code on the system board.