<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
The change Nick suggested is not even few minutes of work to actually implement it, a bit longer to test it.</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
In theory that change can be done at anytime, but it's obviously much safer to do so when the magnet is at 0 amps. It would also be good to set the magnet to some low current (50A?) and make sure the comms reset doesn't actually try and set the current to zero.</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Just to give a block of time, 30-60 minute should be more than adequate. It's easy enough to back out the changes if they don't work as expected. The bigger time sink is ramping the magnets down and back up.</div>
<div>
<div id="appendonsend"></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Probir Ghoshal <ghoshal@jlab.org><br>
<b>Sent:</b> Friday, August 7, 2020 1:27 PM<br>
<b>To:</b> Nicholas Sandoval <sandoval@jlab.org>; Brian Eng <beng@jlab.org>; dsg-hallb magnets <dsg-hallb_magnets@jlab.org><br>
<b>Cc:</b> Eugene Pasyuk <pasyuk@jlab.org>; Ruben Fair <rfair@jlab.org><br>
<b>Subject:</b> Re: MPS Comm Alarm</font>
<div> </div>
</div>
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Brian, Nick,</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
So how long will this take to carryout the work as suggested?</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Eugene - will there be a window/an opportunity to work on when the magnets are at 0 A?</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Please let us know and we can plan out if that is going to be quick (Brian and Nick to suggest)<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Regards</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Probir<br>
</div>
<div id="x_appendonsend"></div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Dsg-hallb_magnets <dsg-hallb_magnets-bounces@jlab.org> on behalf of Nicholas Sandoval <sandoval@jlab.org><br>
<b>Sent:</b> Friday, August 7, 2020 12:32 PM<br>
<b>To:</b> Brian Eng <beng@jlab.org>; dsg-hallb magnets <dsg-hallb_magnets@jlab.org><br>
<b>Subject:</b> Re: [Dsg-hallb_magnets] MPS Comm Alarm</font>
<div> </div>
</div>
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Hi Brian,</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Thanks for this. Yes it is definitely important to reset the MPS comms as soon as possible. If the system tries to initiate a controlled ramp down while communication is lost the PLC will notice it is not progressing as it should and would initiate the MPS
ramp down. Once initiated we cannot recover until back to 0 amps again.</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
having looked at the MPS comm reset it is in the 'initialize' sub routine that we reset the current setpoint to 0 amps, we can easily comment out this portion at the next opportunity.
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
-Nick<br>
</div>
<div id="x_x_appendonsend"></div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="x_x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Dsg-hallb_magnets <dsg-hallb_magnets-bounces@jlab.org> on behalf of Brian Eng <beng@jlab.org><br>
<b>Sent:</b> Friday, August 7, 2020 11:25 AM<br>
<b>To:</b> dsg-hallb magnets <dsg-hallb_magnets@jlab.org><br>
<b>Subject:</b> [Dsg-hallb_magnets] MPS Comm Alarm</font>
<div> </div>
</div>
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<span style="color:rgb(0,0,0); font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">Figured I'd post to the mailing list and get input rather than posting to the entries themselves; regarding the logentries related to this: </span><a href="https://logbooks.jlab.org/entry/3821968" id="LPlnk464765" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt">https://logbooks.jlab.org/entry/3821968</a><br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
If this particular alarm comes up again it probably would it be better to reset it as soon as possible?</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
While nothing is in danger we end up losing most of the software controls when the PLC can't talk with the power supply. Instead it's mostly hardware protection, fortunately during the last long break a lot of faults got moved to a slow dump in hardware, but
best to not let it get that far.</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
The only reason I'd hesitate to make that the SOP is that is as Eugene noted it started to ramp down after resetting, which isn't very surprising. Any suggestions?</div>
</div>
</div>
</div>
</div>
</body>
</html>