[evlatests] problems parking evla antennas

[Barry Clark]

A minor correction.

> > From phicks at nrao.edu  Tue Feb 14 07:31:05 2006
> > Return-Path: <phicks at nrao.edu>
> > From: "Phillip D. Hicks" <phicks at nrao.edu>
> > To: <dmidgett at nrao.edu>, <ms-evla-online-soft at aoc.nrao.edu>
> > Subject: C117666
> > Date: Tue, 14 Feb 2006 07:30:58 -0700
> > 
> > Work status on work order number C117666 is OPEN / AFFECTS DATA
> > 
> > Work Requested:  Report Only.  When a script is running on the Executor,
> > the antenna PARK command doesn't work properly.  The PARK command is
> > being overridden by the script commands.  Upon execution of the PARK
> > command, the commaned position readings change to the appropriate parked
> > values, but after a few seconds they revert back to the postions
> > commanded by the script.  This is the case with antennas 13, 14, & 16.
> > Occurred during file 499S859, L-band, line mode 4, BWC 1111.
> 
> Rightly or wrongly this is documented behavior.  The MIB
> continues driving the ACU for five minutes after the last
> pointing polynomial is sent by the executor and attempts to
> park the antenna in this interval will fail.  This can be
> addressed by 1) having the park command send positions with 
> a new limit time and polynomial terms of zero, or 2) building
> the park command into the MIB, or 3) using the brute-force stow
> utility which overpowers other commanders of the antenna, or 4)
> waiting for the limit time to expire vefore trying to park the
> antenna.

Yes, an attempt to park an antenna while the executor is controling it
will fail.  The script must be aborted or the antenna taken before the 
command will not be overridden.  However, a park command sent after the
scrip termination and before the timeout should be accepted (more or 
less).