<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
Hi all, <br>
<br>
I posted the minutes of todays HPS slow controls meeting at: <br>
<a class="moz-txt-link-freetext" href="https://confluence.slac.stanford.edu/display/hpsg/2013.10.15+Biweekly">https://confluence.slac.stanford.edu/display/hpsg/2013.10.15+Biweekly</a><br>
<br>
Hovanes. <br>
<br>
<h2>Minutes</h2>
<p>Present at JLab: Krister, Stepan, Nerses, Hovanes</p>
<p>Present at SLAC: Sho, Pelle</p>
<h6><a name="2013.10.15Biweekly-SVTInterlock"></a>SVT Interlock</h6>
<p>Hovanes presented some ideas on implementing the SVT interlocks.
The main point was that if we do not need an interlock system that
shuts off the SVT power supplies and the SVT chiller, then we
could use Allen-Bradley PLC for the interlocks since he thinks it
will be relatively easy and reliable system.</p>
<p>Pelle and Sho said that they discussed the issue of the interlock
delay with other SVT experts and they did not see any problem with
100ms delay for the interlocks.</p>
<p>Stepan suggested to get estimates from a dealer to see what the
savings are. Hovanes will try to get an estimate for a system with
modules for the SVT interlocks only, and also for a configuration
with some thermocouples (24 to be precise).</p>
<p>Krister asked if it was possible to use PLC for the HPS stepper
motors as well. According to Hovanes, it is possible to use PLC
for the motors, and many do it, but interfacing with EPICS will
not be as simple, he was pretty sure the the existing EPICS
support for EthernetIP does not include motor record which is the
the record type that Hall B has always been using. Stepan also
thought it would be the best to keep the OMS-based system for the
HPS since there is not enough time for developing and testing a
new system for HPS when we have a working system from CLAS.</p>
<p>Krister and Pelle also suggested that a similar system can be
custom-made using chassis with micro-controllers, so the question
will again come down to the cost efficiency.</p>
<h6><a name="2013.10.15Biweekly-ECALscalerreadout"></a>ECAL scaler
readout</h6>
<p>The question was raised by Hovanes, and was if the scalers from
ECAL will be coming from the FADC250 modules or the JLab
discriminators, in order to be able to prioritize the efforts for
EPICS driver developments.</p>
<p>Stepan said that there has not been a final decision on whether
to keep or drop the JLab discriminators from ECAL, but he thought
that we would gain little by keeping them. Therefore, the we
decided to consider FADC250 scaler implementation in EPICS as a
high priority item.</p>
<h6><a name="2013.10.15Biweekly-Beamline"></a>Beamline</h6>
<p>Krister have not had time to do much work on the beam-line
controls last couple of weeks.</p>
<p>Stepan needs to have the pair spectrometer magnet controls to be
connected to the magnet sometimes next spring when is moved
donwstream.</p>
<p>Stepan also would like to connect the mini-torus power supply to
the old pair-spectrometer magnet since the cables are already
there. Also he would like to be able to ramp one of the Frascatti
magnets to 1050A. Krister pointed out that he will need to check
if the cable ratings are sufficient or he may need to use two sets
of cables. This tests do not need EPICS and can use front panels
of the power supply and the gaussmeter. The Frascati magnet tests
are only for short-term, we will not need to go to 1050 Amps
during HPS.</p>
<p>Krister mentioned that the Dynfysic rep was here at JLab
recently, and he showed the Hall B pair spectrometer power supply
to the rep to see if something can be done regarding the problem
with the current bouncing around by hundreds of Amperes when the
set-point was set to 0Amps. The answer was that it was a common
problem for these types of power supply, and it is possible to fix
it by driving 5A or 10A internally. Noone from present people
objected to this solution, provided we did not have to pay an arm
and a leg for it. </p>
<br>
</body>
</html>