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User name Bob/Kai/Ramesh
Log entry time 08:39:19 on August20,2009
Entry number 285012
keyword=PVDIS crate timing issue resolvedBob, Kai, Ramesh ... We do a few runs changing integration time in Green Monster to check the PVDIS scalers. Recall, one bit is 2.5 usec. Run ..... Integ. Time ..... Result 11451 .... 12000 ....... scalers good 11452 .... 13000 ....... scalers good 11453 .... 13300 ....... scalers fail intermittently (*) 11454 .... 13200 ....... scalers good 11455 .... 13300 ....... fail 11456 .... 13200 ....... good (*) The scaler failure means that there is not exactly 1 event in the FIFO. Could be zero or 2, etc. This is because of wrong timing, see fig 1. This has been understood on a scope. The bottom line is we need the integ time to be not more than 13200 in Green Monster !
FIGURE 1
