[evlatests] multiple subarrays in line mode (fwd)

[Ken Sowinski]

On Thu, 26 Apr 2007, Gustaaf van Moorsel wrote:

> Ken suggested I also test a case where the number of channels
> is different.  So I repeated the above test, with the differ-
> ence that the VLA subarray now observed with BW code 4, or 128
> channels.  The EVLA subarray remained unchanged, at BW code 5
> and 256 channels.
> 
> The result of this second test is that whereas the second sub-
> array (VLA) bandpasses look fine again, the subarray 1 (EVLA)
> bandpasses are complete rubbish.

This has been repaired and I have successfully tested a few
cases.  I encourage further testing if anyone plans to make
use of this.  As of this writing the corrected version of
the system controller code is not installed so consult with
me if any tests are contemplated.

In summary, I expect that the correlator should deal with
multiple line subarrays just as it did before the system
controller was replaced last Fall.  Subarrays which share
an IF must all use it at the same bandwidth; subarrays which
use independent IFs are allowed complete freedom in choice
of bandwidth and the usual correlator options.

Examples.
sub1 in 2AC using (3,x,3,x)
sub2 in 1A using  (4,x,x,x) WILL NOT WORK.

sub1 in 2AC using (3,x,3,x)
sub2 in 1B using  (0,4,x,x) will work.

sub1 in 2AC using (3,x,3,x)
sub2 in 2BD using (x,6,x,6) will work.

The restrictions imposed by the Flukes still apply.  For two
subarrays there is no problem, each will use its own Fluke set;
with three or more subarrays there may be conflicts which will
have to be examined case by case.

All this applies to when the Modcomps are in control.  The executor
does not currently support line subarrays with different correlator
setups, nor the automatic use of both Fluke sets.