[Halld-tagger] tagger microscope Electronics status

[Fernando J. Barbosa]

Hi Richard,

Thanks for the update. It looks like you and Igor have made quite some 
progress and I would say that the prototype costs you mention are very 
reasonable.

Per your time estimates, I would expect that October/November would be 
the right time for me to review the electronics. However, feel free to 
contact me at any time.

Best regards,
Fernando



Richard Jones wrote:
> Fernando,
>
> I think it would helpful for you to have a closer look at our progress 
> on the electronics some time this fall, if you have the time.  
> Meanwhile, here are the highlights after a major push to complete the 
> design and prototyping work this summer.
>
>    1. Work on the readout control board (we call it the "digital
>       board").  This is the most complex component of the readout
>       system, since in involves a computer interface to multiple
>       sensors and the way that the bias voltages on the SiPM's are
>       controlled.  We have three populated prototypes and are busy
>       with debugging.  Several bugs have been found and fixed in the
>       clock generation and distribution scheme that was used.  At this
>       point, the initializatin of the FPGA is proceding correctly, and
>       we see the long startup conversation with the ethernet
>       controller chip completing, and the controller correctly
>       negotiates basic ethernet communication.  However, the wake-up
>       packet that is supposed to be sent upon initialization is not
>       sent over the wire.  Igor has created some useful modular tools
>       in the FPGA program to allow him to debug and discover what
>       about the startup sequence perhaps he has not yet understood. 
>       Progress has been steady, and I expect another few weeks before
>       the digital prototype is completely working.
>    2. Work on the preamp board (we call it the "analog board").  This
>       design has been prototyped and tested on the bench with a single
>       SiPM channel.  Now the design is complete that integrates 30
>       SiPMs (6 columns of 5 fibers each) on a single 6-layer board. 
>       The SiPM's are mounted directly on the preamp board.  The
>       individual amplified outputs from each SiPM are presented on
>       individual output pins, as well as the 6 5-in/1-out column
>       analog sums.   This parts list and gerbers for this design have
>       been presented to a small handful of prototype manufacturers,
>       and we have quotes for 3 boards that are in the $700 range.  We
>       plan to make the order within the next week or so, as soon as we
>       hear whether one of them wants to compete for a
>       build-and-populate bundle price.  We also have quotes from a
>       couple of vendors to populate the boards.  The price for that is
>       in the $900 range.  We will buy the parts ourselves, for a total
>       cost around $2K for three prototypes.
>    3. The interconnect board (we call it the "backplane board").  This
>       board does power distribution to the analog and digital boards,
>       and makes the connections between them.  It also houses the lemo
>       connections that carry the analog outputs to the digitization
>       electronics.  The design is complete and the parts list and
>       gerbers produced.  We have quotes from a number of vendors for
>       production.  Since this board has to provide a light seal to the
>       interior of the box, we are still deliberating over its
>       mechanical specs (thickness, number and placement of holes) but
>       I think we have a plan that will work, at least for the prototype.
>
>
> Richard Jones
>
> Fernando J. Barbosa wrote:
>> Hi Richard,
>>
>> I have not talked to you in some time but I would appreciate if you 
>> could send me an update on the electronics. I know you will provide the 
>> details at the collaboration meeting but I need to provide an overview 
>> of all the electronics.
>>
>> I have talked to you about a review on your electronics some time ago 
>> but I have not had the time and I would like to take a look at the 
>> tagger electronics sometime this Fall.
>>
>> Thanks and best regards,
>> Fernando
>>   
>
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