Wolfgang Koenig build a board were 32 LEDs and 16 meantimers are sitting on. This saves a lot of spavce and equipment. The meantimers are also doing some charge measurement, which will give some ADC information. This is encoded in the length of the signal goind to the TDC.
Until now (Apr06) we used old TAPS discriminators (LED 1600).
After the discriminatorssignal between left and right side are ANDed (also meantimers were used in some test beamtimes). the resulting signal wents to the TDC. Cable delays were needed for old 32chn CAEN TDCs. See next paragraph.
Uses same TDC chips as CAEN v1190. Readout is however different. This solves problems of CAEN TDC (see below). Will be used from now on.
TDC CAEN v1190 (old)
Two of the new CAEN TDC were used in the last test beamtime (Aug05). One for each of the Fiber Detectors. These 128 channel TDC are free running multi hit TDCs. This saves us 192 channels of cable delay and made things a lot easier. At least compared to the old 32 channel TDCs which only work in common start mode. Problem: This TDC runs only in synchronous mode in out setup. Reason is still not know because it was not investigated in detail. Also the TIP board will get problem if the TDC produces too much data!
- 10 Apr 2006