Pdev maintenance procedures

130124: replacing a fileserver with another fileserver
090907: exchanging/replacing pdev spectrometer
090907: Making sure all boxes select external clock
090907: Verifying the synthesizer levels.
090907: updating the a/d offset cal.conf file

Replace a file server:

    Suppose one of the disc arrays on group 0 fails. One quick fix is to replace it with the corresponding fileserver from group 1 (actually you could use any of the file servers in group1). The sequence and things to worry about are:

090907: exchanging/replacing pdev spectrometer

    There are two sets of 7 pdev spectrometers: group 0 and group 1. These can be used for two separate experiments that are run simultaneously.  Each of the 7 bbmixers feeds the same signal into the group 0 spectrometer box and the group 1 spectrometer box. For various software reasons (cal mainly) you must run with group 0, group 1 is optional.

    If a spectrometer box in group 0 dies (eg.. fan failure, fpga overheats) you can replace it with the corresponding group 1 box using the following procedure. Datataking can then continue (but without the group 1 experiment).
Permanent replacement:
If you want to put a new spectrometer box in to replace a failed one:

090907: Making sure all boxes select extclk

    When the power to a spectrometer box is cycled, the spectrometer comes back with the internal clock selected. If you then run cima you may get an error that the clock selection is not the same for all the boxes in use. You can fix this with:

090907: Verifying the synthesizer levels.

    The mock spectrometer uses 3 synthesizers. They are located in the middle rack of the mock spectrometer. They are controlled manually. These are the things to check:

090907: updating the a/d offsets cal.conf file

    The spectrometer uses the file /usr/local/pdev/etc/cal.conf to remove the a/d offsets (it also does scaling but we don't use that). If change a spectrometer box, or the a/d offsets reported while adjusting power is large you should remake the file.
    Remaking the files entails: setting the downstairs if/lo to the noise source and then running pnet with the --sigcal=filename command to regenerate the files. This can be done with a script:

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