From: John Philo <jphilo@mailway.com>
  To  : rasmb@bbri.org
  Date: Thu, 21 Jan 1999 20:42:36 -0800

RE: Help wanted with a serious XL-A data communication failure

Jack,

One thing that can be the source of intermittent communication problems is
the energy conservation features on the computer.  When you are away from
the computer and not touching the mouse or keyboard, the computer goes into
'sleep' mode and in some cases actually shuts down the serial communications
port. Screen savers are also a potential source of problems.

In principle the machines supplied by Beckman are supposed to have these
energy conservation features disabled, and in principle the service people
know about this and check for it.  However, I have run across at least 4
machines in which the energy conservation stuff was NOT disabled.

In this regard, you need to be aware that it is not sufficient to just
disable the power conservation features in Windows.  You also need to
disable them in the BIOS settings, which you do typically by hitting F1 or
ESCape while the computer is booting.

John Philo
Alliance Protein Laboratories


-----Original Message-----
From: Jack Lebowitz [Jack_Lebowitz@micro.microbio.uab.edu]">mailto:Jack_Lebowitz@micro.microbio.uab.edu]
Sent: Thursday, January 21, 1999 12:45 PM
To: rasmb@bbri.org
Subject: Help wanted with a serious XL-A data communication failure


Dear RASMBers

We have a serious XL-A problem, that I will relate below, which may be
isolated only to our XL-A  or it could be a more wide spread problem that
others have encountered. Consequently,  I would like to know if other
investigators have had a similiar problem and how it was were resolved.
Around March 98 we purchased a 8 cell rotor and the new 4.0 XL-A software.
The latter required new EPROMS. After installation of the software and
EPROMS we had continual intermittent communication errors and the XL-A would
stop scanning. After a long protracted process of changing EPROMS and the
data acquistion board, and then finally a very extended visit by our field
engineer to completely check out the instrument the problem appeared solved
since we were able to run experiments for about 7 months. However, it
reappeared in late November. We were told by our field engineer that Beckman
was aware of communication problems and was rewriting ROM for the XL-A
EPROMS which now required their new version 4.5 software.  New EPROMS and
the 4.5 software were installed. An initially test run of 80 scans with a
water cell looked good but the very next real experiment failed very early
in the run due to a communication error. COM errors are totally
unpredictable, we turn off the XL-A and start a new experimental setup and
it could be fine or fail at any time in the experiment. We have switched
computers and tried version 3.01H XL-A/XL-I software and once again the
pattern of failure is unpredicatable.  The last test suggests that the
problem does not emanate from the computer but is an XL-A problem. Obviously
we need to solve this problem in order to have a truly functional XL-A and
welcome any help we can get towards a resolution. Thanks very much for any
input.

Sincerely,

Jack Lebowitz


Jack Lebowitz
Dept. of Microbiology
520 CHSB
Jack Lebowitz
University of Alabama at Birmingham
Birmingham AL 36294-2041
(205) 934-9475
FAX (205) 975-4621