[evlatests] the L302 amplitude glitch

[Bryan Butler]

could this be related to the "three waveguide cycle tick" issue?  i commented 
that part out of obs2script as barry had implemented it directly in the 
executor, so it shouldn't make a difference whether it goes through obs2script 
or not, but if there is something in the way it's implemented in the executor 
that cares about time then it might be a culprit...

	-bryan


On 6/3/06 14:38, Ken Sowinski wrote:
> On Wed, 31 May 2006, Ken Sowinski wrote:
>>
>> After examining the data on disk, I can confirm that I saw no
>> no glitches and that Walter did.  Differences?
>> 1.  Different executor.
>> 2.  I had the source marked as a calibrator, but Walter did not.
>> 3.  Modcomps were rebooted inbetween the observations.
>> 4.  Different HA.
>> It is hard to see that any of these are relevant.
> 
> There are two more variables:
> 1.  I used Xsysstart; Walter his own file.
> 2.  The scripts were started at different instants.
> 
> One of these might be able to explain what I am about
> to describe.
> 
> We used some dynamic time this afternoon to examine the
> glitches more carefully.  Three different observations
> were attempted.
> 1.  I ran the EVLA antennas using Xsysstart and an up to
>     date local copy of the executor.
> 2.  We ran a file devised by Walter which does only X band
>     and was run by the operator.
> 3.  We will try to run the same file as last week, which
>     cycled over all the bands several times.
> 
> I write this as 2. is in progress.
> 
> 1.  When I ran Xsysstart I saw no glitches on any IF
> examining antenna 4 x 13.
> 
> 2.  I had the operator start Walter's simple X band file
> at about 0520 LST.  It worked file until 0530 LST which
> was its sceduled start time and then the usual glitches
> appeared.  I asked the operator to kill the script and
> the glitches ceased.  I then ran the same script using
> my executor and the glitches were present.  Again the glitches
> ceased when I killed the excutor I was running.
> 
> At 2001 IAT I asked the operator to run the Xsysstart script,
> and no glitches were seen.  This script was killed at about
> 2003 IAT.  Then Walter's sript was started again and no
> glitches were seen.  Over time however the amplitude slowly
> devreased and phases started winding; it looked like the
> executor was not really running, or not sending commands
> to the antennas.
> 
> 3.  Walter's seoond file was started at 0600 LST and I
> see glitches at X band.  I leave it to others to examine
> this dataset more careully to see what mysteries might
> lie there.
> 
> 
> Tentative conclusions
> 1.  There is a difference between Xsysstart and other
> scripts, or,
> 2.  Whether glitches occur or not depends on exactly when
> the script is started.
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