Re: Recurrent serial port problems
David larkin (pointers@iol.ie)
Mon, 1 Apr 1996 12:42:06 +0100 (BST)
At 17:06 26/03/96 -0500, you wrote:
>
>I have a problem currently with the Omnigo and communications.
>Everything has typically been fine with data transfer (except for
>format conversion of course) and program loading, etc. Probably a month
>ago I tried to connect to my PC and was not able to establish a
>connection with any program (conn. pack, installer, quicken connect).
>
> After nearly pulling my hair out, hard rebooting etc, to no
>avail; it suddenly "self-repaired" about a day later. just hooked it
>up and everything seemed okay. I used to be a process engineer in a
>former life and I HATE when things "self-repair", because you just know...
>
>Same thing happened this past weekend, and it is still out there. This
>time around my i/o board got totally smoked while I was trying to coerce
>the OGO to speak. I had the PC apart to switch the cable etc. do I have
>no idea what the cause was. The OGO seemed no different so I assumed that the
>i/o
>board was to blame. I replaced it, but still no go. Laplink, graphics
>tablet, etc all seem to function fine from the port. The symptoms are
>identical in that while none of the programs will establish a connection,
>they behave differently if the baud rate on the OGO is changed. In
>addition when the connectivity pack gives up trying, the OGO drops out of
>the connect mode as it should. This makes me skeptical of the cable
>being the culprit along with the act that I tried to recreate the problem
>before by jiggling the cable, etc. with no success.
>
> If anyone has any suggestions or ideas I would love to hear
>them. The cable has always been inserted right side up and all that good
>stuff. If the comm port on the OGO is bad, I will be a very unhappy
>camper as I cannot fathom anyone covering that under warranty, and I am
>not going to send > 50% of the machines cost. Sullenly yours.
>
>WHM
>
>
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Warren H. Minix ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Center for Molecular and Engineering Thermodynamics ~~
>Colburn Laboratory ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Newark, Delaware 19716-3110 ~~~~~~~~~~~~~~~~~~~~~~~~~~
>U.S.A. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
This isn't the first time I have seen serial problems with low voltage devices.
The problem seems to be with the the interpretation of the RS232 standard.
Manufaturers seem to work to the min. voltages (plus/minus 5v) specified
under RS232 instead of the design voltages (plus/minus 12v). With only 3v
supply this would seem to fit the bill and, if I ever get the time, I will
put a trace on the OGO comm port.
Subsequently wierd and random shit happens. If the batteries are low then
the comms won't work or if the comms card in the PC doesnt like less than 7v
then there will be problems.
David Larkin
----------------------------------------------------------------------
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89c Lagan Rd., Fax - intl + 353 1 8300543
Dublin Industrial Estate., e-Mail- pointers@iol.ie
Dublin 11,
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