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Hi Don,</div>
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Glad to hear your testing is going well with the DSG designed control system. We will discuss your request to add the functionality of operating without the PID and let you know how we plan to proceed.
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As far as moving the controls equipment to Hall A, I will let you know our plan after we discuss it in our meeting. There are some changes to networking which will need to happen before the controls will be available in the hall.
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When we have the full scope of the controls move developed, I will setup a meeting and inform everyone.</div>
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Regards,</div>
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Marc<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Donald Jones <jonesdc@jlab.org><br>
<b>Sent:</b> Tuesday, August 29, 2023 9:54 AM<br>
<b>To:</b> dsg-halla_ecal@jlab.org <dsg-halla_ecal@jlab.org>; Marc Mcmullen <mcmullen@jlab.org><br>
<b>Subject:</b> Re: ECal controls update</font>
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<span class="x_elementToProof x_ContentPasted0" style="font-size:12pt; margin:0px">Hi Marc,</span>
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I have turned off the heaters and pointed the fan at the rear of the crystals to cool things off faster. I would like to get started on swapping out sensors ASAP and then move the system to the Hall tomorrow or Thursday.</div>
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I really love the current readout. I learned a lot about the system already. One thing I learned is that if you are underutilizing the supply current like we are, the upper end of the PID output is not useful. For example, each SM zone has only 4 heaters where
we could actually service 13 heaters and still fall just under the 12.5A current limit. At maximum voltage we are only drawing about 4.2A or 34% of maximum. Because of this, the control voltage saturates at 3.4V on the SM zones and anything above this does
nothing since maximum current for this number of heaters has been reached. When the control voltage drops below 3.4, the current starts to reduce proportionally again. When you are well below the setpoint temperature the control output gets set to 10V and
then slowly drops over a half hour, but the current doesn't change until it goes below 3.4. It's not the way I would have designed it, but ok. I don't think the adjustment sensitivity should depend on the load. I would much rather have the output adjust voltage,
but I guess current is the right thing if you are driving LEDs. It just shows me that we need to design the final system with zones drawing close to the maximum current capacity of the supplies in order to maximize our control sensitivity.</div>
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I have one more request if it's not too difficult. Can you add to the program the ability to disable the PID and simply set the output voltage to a given value? Once the system is close to equilibrium it becomes obvious what that voltage setpoint is, and it
will allow us to eliminate any PID oscillations. We will be left with the usual +/- 1 degree ambient temperature variations, but those are small enough to not worry us.</div>
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-Don</div>
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Donald Jones</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Hall A/C Staff Scientist</div>
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Jefferson Lab</div>
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Newport News, VA</div>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Dsg-halla_ecal <dsg-halla_ecal-bounces@jlab.org> on behalf of Marc Mcmullen via Dsg-halla_ecal <dsg-halla_ecal@jlab.org><br>
<b>Sent:</b> Tuesday, August 29, 2023 8:51 AM<br>
<b>To:</b> dsg-halla_ecal@jlab.org <dsg-halla_ecal@jlab.org><br>
<b>Subject:</b> [Dsg-halla_ecal] ECal controls update</font>
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Hi,</div>
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DSG has completed the latest update for the ECal controls which includes the following improvements:</div>
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<li style="list-style-type:disc"><span>Configuration file for the PID settings</span></li><li style="list-style-type:disc"><span>Current monitoring for each heater channel (5 channels)</span>
<div style="list-style-type:disc"><span><span> <img class="x_x_w-1630 x_x_h-1070 x_x_ContentPasted0" id="x_x_imageSelected0" size="184743" width="466" height="307" data-outlook-trace="F:3|T:3" src="cid:c9d6dc7a-c489-4fef-94d4-88bea41c42fc"></span><br>
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</li><li style="list-style-type:disc"><span>Current monitoring display for the GUI</span>
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<div>The software is currently running as a Real-Time application on the cRIO. Should the software stop running the Watchdog software will reboot it to a safe state, with all heaters off. But the setpoints and PID settings will return.
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<div>DSG will monitor the system until it is shutdown and moved to Hall A.</div>
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