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John Ford wrote:<br>
<blockquote type="cite"
cite="mid60815.67.138.230.174.1132628687.squirrel@webmail.gb.nrao.edu">
<pre wrap="">I think the best solution for this is to figure out how to back it up over
the network. I don't want to modify the hardware, particularly the
packaging, at this point.
John
</pre>
<blockquote type="cite">
<pre wrap="">While writing up the backup/restore procedure for the CCB, it occurs
to me that backing up the CCB and restoring it to other CCBs could be
a significant headache in the future, as things stand currently. In
all cases, to do this one currently has to undo all of the bolts
around the top of the CCB, and then either backup in-place, over the
net, by plugging in a USB CDROM drive with a live-CD, and performing a
dump of the microdrive over the network to a remote computer, or
alternatively temporarily dissasemble the computer card-stack, remove
the microdrive and place it in a workstation flash-card reader to
perform the backup/update.
I'm thus wondering if it might be worthwhile to add a small access
plate with a USB socket behind it, to the front panel of the CCB. The
access plate would be bolted in place, for shielding, when the CCB was
on the telescope. To backup or update a given CCB, we would then
remove the few bolts holding this plate in place, in order to plug in
a CDROM drive with a live-CD in it. One would then boot the CCB from
the live-CD, and use its dump program to backup or update the
microdrive to/from a disk on another computer. This could probably be
done on the telescope, during maintenance sessions.
In addition to easing the logistics of backups, this would presumably
reduce wear and tear on the bolts and gaskets of the lids of the CCBs.
Note that I'm not anticipating frequent changes that need to be backed
up. So it may not be that important.
Martin
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</blockquote>
All,<br>
<br>
I agree with John...<br>
<br>
With regards to potential RFI (and the lack thereof)...<br>
<br>
Given the fact that the CCB has a CPU clock fundamental of 933MHz<br>
and that its five FPGA's are capable of upwards of 300MHz switching<br>
rates (with harmonics stretching well into the GHz range), the
instrument,<br>
in it's current physical configuration, is amazingly
"stealthy"!<br>
<br>
Indeed, during chamber testing, the CCB exhibited only three "birdies"<br>
(<u>barely</u> detectable!); all of which lie within the 900-1000MHz
range<br>
and all of which were only 10Hz wide! To be such a powerful beast,<br>
the thing is unprecedentedly RFI quiet! Once processed through our<br>
RFI acceptance spreadsheet, the CCB passed with flying colors with<br>
some 11dB to spare under our most stringent acceptance criteria. <br>
<br>
With this in mind, unless absolutely necessary, I feel it
would be unwise<br>
to alter its packaging design in any way...<br>
<br>
Randy<br>
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