Embedded controller for GEM detector data acquisition system

This paper describes the embedded system used to control the multichannel data acquisition system (DAQ) for the GEM detector.
The controller is based on an embedded Mini ITX mainboard, running the GNU/Linux operating system.
The system offers two interfaces to communicate with the FPGA based DAQ. FPGA configuration and diagnostics is controlled via low speed USB based interface, while high speed setup of DAQ and reception of the measured data is handled by high speed PCIe based interface.
Hardware access is synchronized by the dedicated server written in C. Multiple clients may connect to this server via
TCP/IP network, and different priority is assigned to individual clients.
Specialized protocols have been implemented both for low level access on register level and for high
level access with transfer of structured data with "msgpack" protocol.
Additionally status of the system may be monitored via web interface.