[Halld-tracking-hw] [GlueX] Hall D cables

[Fernando J. Barbosa]

Hi Yves,

There are 24 channels on a preamp with differential outputs and there is 
one differential pair for the test signal going from the fADC125 (or the 
F1TDC in the case of the FDC sense wires) for a total of 25 pairs on the 
cable. The shield of the cable is grounded through the 3M 50-pin 
connector (attaches to the fADC125 or F1TDC). There are no grounding 
leads on the signal cable. The grounding of the electronics (preamps, HV 
and LV) is made at the detector to the hall ground which is where all 
the instrumentation is referenced to. For further details, please refer 
to the grounding, HV and LV distribution documents on the electronics 
wiki or the portal.

Thanks for the feedback and best regards,
Fernando



Yves Van Haarlem wrote:
> Hi Fernando,
>
>>> - What about cables for pre-amp test signals? As the LV cabling 
>>> still has to come and LV + test signals end in a single connector on 
>>> the HV board, we assume test signals will be done together with the LV.
>> The Amphenol cable has 25 pairs and one pair is used for the test 
>> signal which is generated on the fADC125.
> I am confused: the signal coming from the preamp is differential. so I 
> thought you need 24 pairs for the signals + at least 1 single lead 
> (probably one pair) for ground, so there is no room for the test 
> signal? Or what is the grounding scheme?
>
> Cheers,
>     Yves
>
>
>
>
>
>
>>
>> Thanks for the feedback.
>>
>> Best regards,
>> Fernando
>>
>>
>>
>>
>>>
>>> Cheers,
>>>     Yves
>>>
>>>
>>>
>>>                           /--------------------------------
>>>                          /   Yves Van Haarlem
>>>        _--~~--_         /
>>>      /~/_|  |_\~\      /      Carnegie Mellon University
>>>     |____________|    /        Department of Physics
>>>     |[][][][][][]|:= /          Wean Hall room 8404
>>>   __| __         |__ \            Pittsburgh, PA 15213
>>>  |  ||. |   ==   |  | \           USA
>>> (|  ||__|   ==   |  |) \
>>>  |  |[] []  ==   |  |   \           Tel.:   +1 412 268-6949
>>>  |  |____________|  |    \                  +1 412 641-9252
>>>  /__\            /__\     \          Fax.: +1 412 681-0648
>>>   ~~              ~~       \-----------------------------------
>>>
>>> On Sat, 13 Mar 2010, Fernando J. Barbosa wrote:
>>>
>>>> Hello everyone,
>>>>
>>>> I have attached a pdf with a list of signal and HV cables for use 
>>>> in Hall D. This list will be later expanded to include the LV and 
>>>> optical fiber cables and it will form the basis of a formal 
>>>> specifications document. The cables listed connect the various 
>>>> detector sub-systems to instrument racks.
>>>>
>>>> The cable lengths, with routing allowances for trays and racks, 
>>>> have been checked with the Hall D mechanical group; the suggested 
>>>> actual length of the cables have been rounded up to allow grouping 
>>>> among different sub-systems and minimize cost and part numbers. The 
>>>> nominal cable rating is NEC UL CL2 and cable part numbers are 
>>>> suggested.
>>>>
>>>> The types of connectors (no actual part numbers at this time) are 
>>>> included for the source and destination (the readout modules use 
>>>> Lemo-style connectors).
>>>>
>>>> Due to accelerated procurement initiatives by the 12GeV management 
>>>> team, I am requesting the following information and feedback, where 
>>>> appropriate, by the end of next week (3/19/2010) from the 
>>>> collaboration and from the various detector subsystems:
>>>>
>>>> 1. Cable type & ratings (with anticipated HV operation levels of 
>>>> PMTs, for example)
>>>> 2. Length
>>>> 3. Connector types (source and destination)
>>>>
>>>> My plan is as follows:
>>>>
>>>> 1. Request info/feedback from collaboration (this)
>>>> 2. Finalize specifications document
>>>> 3. Submit formal specifications document to Dianne (12GeV 
>>>> Integration) for submission to the JLab Electrical Safety Committee 
>>>> and approval
>>>> 4. Outline procurement plan with the JLab procurement dept.
>>>> 5. Procure cable assemblies from vendors.
>>>>
>>>> I note that some detectors are not completely defined for the final 
>>>> configuration in the hall but the number of cables from these 
>>>> detectors is relatively small. I would appreciate if you could 
>>>> provide information as to the procurement readiness for such 
>>>> sub-systems.
>>>>
>>>> Thanks for your prompt feedback in advance.
>>>>
>>>> Best regards,
>>>> Fernando
>>>>
>>
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