[evla-sw-discuss] [Fwd: Re: [evla-mc] More on MIBs...]

[Bill Sahr]

-------- Original Message --------
Subject: Re: [evla-mc] More on MIBs...
Date: Thu, 6 Dec 2001 09:15:15 -0700 (MST)
From: Kevin Ryan <kryan at aoc.nrao.edu>
To: kryan at zia.aoc.NRAO.EDU, bwaters at zia.aoc.NRAO.EDU
CC: gvanmoor at bclark.aoc.NRAO.EDU,
browen at bclark.aoc.NRAO.EDU,kryan at bclark.aoc.NRAO.EDU,
ghunt at cv3.cv.nrao.edu,bwaters at bclark.aoc.NRAO.EDU,
bclark at bclark.aoc.NRAO.EDU,wkoski at bclark.aoc.NRAO.EDU,
gpeck at bclark.aoc.NRAO.EDU,pnapier at bclark.aoc.NRAO.EDU,
rperley at bclark.aoc.NRAO.EDU,ksowinski at bclark.aoc.NRAO.EDU,
pperley at bclark.aoc.NRAO.EDU,phicks at bclark.aoc.NRAO.EDU,
fowen at bclark.aoc.NRAO.EDU,tcornwell at bclark.aoc.NRAO.EDU,
Brent.Carlson at nrc.ca,Peter.Dewdney at nrc.ca, bsahr at cv3.cv.nrao.edu,
bclark at zia.aoc.NRAO.EDU,kryan at ozone.aoc.NRAO.EDU



Thanks for your thoughts on this subject Boyd and Barry.

Boy did I ever screw-up when I put that MIB driver block in
my diagram!  All it meant to convey was a distinction in 
communication paths between the Antenna Controller and the 
Array Controller and between the Antenna Controller and the MIB

Instead, my use of the word 'driver' put thoughts of detailed, 
MIB control-level functionality up in the Antenna Controller; 
the exact _opposite_ idea that I wanted to convey.  

If design is carried out the way I believe it should be, there will
be no need for drivers in the complex way that we think of them now. 
The MIBs will know how to drive themselves once told 'where' they 
need to go.

Even if he could, a doctor would not tap into your brain to
diagnose why your ankle is in such pain.  He would talk to you
as a whole person entity, find out that your ankle hurt, then
probe around that immediate area using special tools such as an
X-ray machine to see if you broke a bone.

The Antenna Object (AO) is the essence of an antenna.  The laptop 
would look at the antenna as a whole (by talking to the AO), see 
that the AZ servo is not responding, then look directly at the AZ 
MIB with his own special diagnostic routines to isolate the point 
of failure.

If John Dreher and others had grasped that concept from my talk,
he (they) would realize that the statement he made about the
Tech's laptop sharing the same drivers was logically non sequitur.

Obviously I failed to properly convey my thoughts on modularity and 
objects. I noticed confusion in this area prior to the PDR and during
other people's talks during the PDR.  To clear this up in preparation 
for the AMCS design phase that will soon be upon us, I planned to do 
a short write up on 'the modular array'.  It will probably become the 
introduction to the official EVLA AMCS Design Specification.

Kevin