We want to find a way to check the mapping of the epd from the FEEs through the QT.  The idea is that if we change the vped setting in a given channel, we should see the pedestal shift.  Then we would use the bfc to create a mudst and make sure that the ew/pp/tt of that tile correspond with what we expect from the qt/board/ch.  (We would look at the latter using the .dat files.)  Currently the cabling between the QT and the diff-Rx boards is not complete, so right now we are testing.  When looking at a scope, we saw that the DC offset changed considerably as we changed the vped, so this should work.  (We have also had comments about the large pedestals from the trigger group, and our default setting is 20 which is a little higher than last years' average of 11.)

In order to have a maximum difference, I set the vped to -90 in every channel and then asked Joey to take a pedestal rhic-clock clean. (19044047)

We then took 5 pedAsPhy runs (run # is 19044 in front)

First: run048 - vped -90.  This should be the default, I would expect all of the values to be around 0.  If you look in the attached pdf, they are not.  This is odd.

run049 - vped - ch0 to +90 .  This run I had meant to only turn those channels hooked up to a QT ch 0 to 90 and leave the rest at -90.  Unfortunately, I actually changed the other channels back to my default of 20.  Opps.... I'd expect all of them to change, but they didn't.  However, those that showed up with a pedestal in run 48 did so again for the most part.

run050 - vped - ch1 to +90 - Same as 049 but instead of QT ch 0, I changed QT ch 1.

run051 - vped - EW0PP1 - In this run, I changed all the channels associated with PP1 on the east side to 90.  (Others still bumped up to 20.)

run052 - vpec -    EW0TT1  - In this run, I changed all the channels associated with all of the TT1 on the east side to 90.  (Others still bumped up to 20.)

The results of 048-050 from EQ1 can be found at:
drupal.star.bnl.gov/STAR/system/files/Compare_19044048to50.pdf

Basically all QT32Bs show no movement.  Basically all QT32Cs show a pedestal.  And there doesn't seem to be much of a difference between the 3 options in many.... Though there are some channels that seem to have a nearly zero run 048, which I would expect (but not really since they went from vped = -90 to 20), and then some value for run050 and run049, but these seem to match channel by channel which I would not expect.

Obviously, we are doing something wrong (which is why we started playing with this now).  Thoughts:
vped = -90 is too extreme and that chokes the system in a weird way.
The Tier 1 file is wrong
The pedestals weren't taken correctly

There are probably other reasons, but I will return to this problem tomorrow.