[RASMB] CPU Board Malfunction on XL-I

[John Philo]

Just to clarify my earlier response, I was addressing only one of several
different issues that can cause data acquisition stoppages. Many of the
issues discussed in subsequent messages are due to serial communication
issues between the PC and the DAB board in the instrument. The CPU overload
problems I talked about vary only with the version of the firmware, whereas
the serial communication issues depend on the firmware version, the GUI
version, and also I believe with the specific PC hardware. I have heard it
said that Beckman has seen variation in the extent of the serial
communication problem even within the same model # of IBM computer due to
changes in motherboard components, but I can't confirm that is true. What I
do know is that my XL-I and XL-A never seem to have stoppages due to serial
communication issues, so there are actually combinations of firmware/GUI/PC
where this is minimal.
 
Definitely power line fluctuations are problematic, but those will normally
produce a different error message. The DAB CPU overload issue I discussed
will not necessarily produce a Diagnostic 11 error message. 
 
John

  _____  

From: rasmb-bounces at rasmb.bbri.org [mailto:rasmb-bounces at rasmb.bbri.org] On
Behalf Of Ute Curth
Sent: Friday, March 11, 2011 3:05 AM
To: rasmb at rasmb.bbri.org; ian.berke at yale.edu
Subject: Re: [RASMB] CPU Board Malfunction on XL-I



Hi Ian,


we bought an XL-I equipped with an Aviv AU-FDS in 2008 and also suffer from
severe problems. Either the centrifuge stops spinning or the computer stops
scanning within a run. This happens after unpredictable times (20 min to 20
hours), at different rotor speeds (e.g. 22, 35 or 50 krpm), independent
whether we measure absorbance only or absorbance and interference but not in
every run. Our machine is still under warranty and Beckman has been trying
for more than one year to solve this problem. A lot of components of the
machine (all boards, the display, the radial drive....) were exchanged, but
this did not solve the problem. After having ruled out that there were
problems with the power supply in our institute, they admitted that there is
a timing problem in the communication between centrifuge and computer and
that similar problems exist in about 10 machines worldwide. Therefore, they
modified the firmware and installed a new firmware pre-release (now the
machine stopped scanning regularly in runs which were performed at 50000
rpm) and afterwards a new version of the GUI, which should solve this
problem. In first tests with the new firmware/GUI combination the machine
seems to work more reliable (it did not stop in several test runs at several
speeds), but it turned out that the new firmware is not able to hand over
the correct value for w^2t to the computer (a plot of w^2t against the time
is not linear as expected, but looks like a saw tooth wave).  They are
trying to solve this problem for several weeks now and I still hope that our
centrifuge will work properly soon. Just as a comment: the Aviv fluorescence
detection system works without any problems.


Best wishes

Ute

-- 

PD Dr. rer. nat. Ute Curth

> Medizinische Hochschule Hannover

> Strukturanalyse

> OE 8830

> Carl-Neuberg-Str. 1

> 30625 Hannover

> Germany

> 

> Tel.: +49-511-5329372

> Fax : +49-511-5322909
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