This paper describes the embedded controller used for the multichannel readout system for the GEM detector. The controller is based on the embedded Mini ITX mainboard, running the GNU/Linux operating system. The controller offers two interfaces to communicate with the FPGA based readout system. FPGA configuration and diagnostics is controlled via low speed USB based interface, while high-speed setup of the readout parameters and reception of the measured data is handled by the PCI Express (PCIe) 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. High level functionalities have been split between multiple TCP/IP servers for parallel operation. Status of the system may be checked, and basic maintenance may be performed via web interface, while the expert access is possible via SSH server. System was designed with reliability and flexibility in mind.

Date Published: 25 October 2013
PDF: 12 pages
Proc. SPIE 8903, Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2013, 89032N (25 October 2013); doi: 10.1117/12.2033281

Published in SPIE Proceedings Vol. 8903:
Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2013
Ryszard S. Romaniuk, Editor(s)