I repeated the same study but now with all_v2 for SSP and kp22 for trigger. System does not get stuck but it takes zero events each spill and keeps doing it, despite the fact that there is beam. DYC1 DYC2 DYC3 DYC4 DYC5 DYC6 .............................................................. Normal work prmt empty empty prmt empty empty empty empty .............................................................. kp22 prmt empty empty prmt NONE NONE empty datain .............................................................. kp22 prmt NONE NONE prmt empty empty datain empty .............................................................. kp22 prmt empty empty prmt NONE NONE empty datain .............................................................. kp22 prmt empty empty empty prmt datain empty datain .............................................................. kp22 prmt empty empty prmt NONE NONE empty datain .............................................................. kp22 prmt NONE prmt empty empty empty datain empty .............................................................. Well, I do not see any particular pattern, or any particular DYC to blame. Smells like some out of time fast clear, not certain though.... Sasha.