[Halld-controls] RTD system for BCAL

[Elliott Wolin]

Dear Elton, Yi and Jim,

One of you mentioned to Hovanes about 96 RTD channels needed for the 
BCAL cooling system.  I think it would be best for one of you to give an 
informal presentation at the next Controls meeting (Thurs 31-May 9:30am) 
outlining your thoughts and requirements.  This would launch the 
back-and-forth discussion needed to get you what you need in a way that 
is best compatible with the overall control system and one that 
minimizes cost (Josh is checking with the A-B salesman and Cryo group 
for alternative solutions).

Additional concerns beyond just supplying 96 RTD channels include the N2 
supply, backup N2 supply, strategy to deal with power and/or N2 loss,  
sensors for monitoring humidity and perhaps flow rates, fault detection, 
response to faults, etc.

In general a PLC-based solution seems best.  Even if the up-front 
hardware costs are higher, programming and long-term maintenance costs 
should be minimal.

Thanks,

-- 

				Sincerely,
					Elliott


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  Those raised in a morally relative or neutral environment will hold
		    no truths to be self-evident.
				

Elliott Wolin
Staff Physicist, Jefferson Lab
12000 Jefferson Ave
Suite 8 MS 12A1
Newport News, VA 23606
757-269-7365

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