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User name V. Sulkosky
Log entry time 20:44:54 on February 17, 2011
Entry number 347390
keyword=EDTM Setup Checkout
I spent the better part of the day checking the EDTM setup for the
simulation of the coincidence trigger. Almost all the numbers I have
gathered have been verified extremely well. However, I did find one
oddity that I do not completely understand. On the left HRS after the
EDTM signal comes from the BB weldment, I expect there to be about 180 ns
of delay between the patch panel and the front output from the S1 EDTM
module:
4 ns Lemo to FI/FO
5 ns Internal delay FI/FO
16 ns Lemo to EDTM slave
155 ns Internal EDMT delay
------
180 ns
I verified that the delay from the back output to the front output is
155 ns. However, when I measure the total delay from the patch
panel
to the S1 front output I measured 224 ns! For some reason,
there
is an extra 44 ns that I was not expecting. I have not
directly
measured the 16 ns lemo cable, but I strongly doubt it is
60 ns. I updated my calculations with this new piece of information,
which makes
a small change in what I was using previously (+22 ns)
in the EDTM setup.
I made a similar measurement on the right HRS, and I did not find any
discrepancies.
In fact, the numbers were prehaps too good, if
possible.
A copy of this log entry has been emailed to: brads