MWPC-readout with the N110 TDC under Linux using a flexible, low-cost FPGA solution

For X-ray spectroscopy at the plasma physics tokamak TEXTOR in Forschungszentrum Julich three N110 TDC modules (developed by Christian Herve, ESRF, Grenoble) are used for the readout of multi-wire proportional counters (MWPC). An optimized low-cost FPGA-based CompactPCI board was developed, that interfaces the N110 and the TEXTOR timing system. The implemented software consists of a Linux device driver and a measurement application program. The Linux device driver is responsible for the transfer of list-mode detector and timing data via DMA into the main memory of a PC. After each TEXTOR shot the application program transfers the data from RAM to disk and adds administrative shot information automatically. Three boards can be read out by one PC simultaneously at the maximum speed of the N110.