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This report covers the last week Reporting for: Dan Callahan Susanne Kyre Stephen Jaditz Puneeth Kalavase Jim Lamb. Status of Rod Production at UCSB. assembly. testing. Tests of I2C errors. Visit from Guido Magazzu & Wim Beaumont June 3 to June 7 Following the visit at FNAL
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This report covers the last week Reporting for: Dan Callahan Susanne Kyre Stephen Jaditz Puneeth Kalavase Jim Lamb Status of Rod Production at UCSB assembly testing
Tests of I2C errors • Visit from Guido Magazzu & Wim Beaumont June 3 to June 7 • Following the visit at FNAL • Report available • http://hep.ucsb.edu/cms/rod/I2c_230_investigation_v.1.2.doc • To make a long story short, problem is due to different RC on I2C clock lines going to hybrid and optohybrid • Causes wavefronts to change at slightly different times • See http://hep.ucsb.edu/cms/rod/TheGreatI2CMysteryv2.ppt
FE-Hybrid 82W Parasitic on FE Hybrid CH SCL SDA AOH CH > CA Parasitic on AOH CA 82W Present Electrical circuit
(Main) Solutions under investigation • R=82 Ohms R=0 Ohms • As implication for power-on sequence. • Would need to power-on control and F.E. at the same time • Most robust from I2C stand point • Tune one of the R to equalize RC • R to AOH ~ 820 ohm • Jumper across resistance (see picture next page) • Forces same RC
Solution 6 FE-Hybrid 82W Parasitic on FE Hybrid CH SCL SDA AOH Parasitic on AOH CA 82W PSU Control PSU FE before
Other stuff • Still fighting coolant leak • Isolated to flowmeters inside fridge • Catalog says: flowmeters have vitan o-rings • Vitan is "bad" with C6F14 • Took it apart, observed damaged o-rings Solving this is highest priority to be able to begin production when I2C business is settled