Log entry time 12:32:19 on March 16, 2012

Entry number 366686

This entry is a followup to: 366649

Followups:

• 366730 03/16/12 17:19 M. Cummings Signal from patch panel Betty C8 on RHRS

Last night the T1 rate was unexpectedly low.  This morning Vince and I
looked at T1 to see if there were any obvious problems.  The timing of T1
seems normal; the overlap between s1 and s2 is ~30ns.  

One oddity that was found was that the module creating T1 (PS754) has a
questionable logic switch.  That is, the dial used to set the "and"
between outputs (set to "2" in the current configuration) does not go to
the maximum value of 4, but goes well beyond the minimum value of 1.  We
moved T1 to a different channel of the module.  The rate with cosmics
seems normal, both for the "and" and the "or" of s1 and s2m.

We also checked the busy for the 3 crates going into the TS2 module; it
appears to be normal at 11.4 micro-sec.  

Vince ran a test to check the rate of the slow clock.  He used scread,
and found that the rate was as expected.  We also took a series of runs
using the fast clock as T8 instead of the slow clock.  We saw ~3%
deadtime for a rate of 5kHz, and about 10% for a rate of 6.5kHz, which is
what we would expect.

The rate looks normal with cosmics, but we will have a better idea when
the beam comes back.