Re: 6400 Printer problem

Dear Steve,

Twinax communication over UTP cabling is very
susceptible to failure due to electrical interference
from outside sources near the cabling infrastructure.

You can download a white paper (pdf document) from
IBM's web site 
http://www.networking.ibm.com/pdf/emexptr.pdf 
titled Technological Advances in Twinax Communications
(published Sept. 1997). The white paper is 14 pages
long and it includes all the IBM recommended cabling
distances by media type on pages 12 & 13. 

The specifications for CAT 3 and CAT 5 UTP cabling to
carry the standard IBM Twinax Data Stream are listed
in the IBM publication GA27-3749 IBM 5299 Terminal
Multiconnector Model 3 Planning, Setup, and
Maintenance Guide. 

The specifications from Appendix B: of publication
GA27-3749 are listed below:

?  #22 or #24 AWG (American Wire Guage)

?  Solid copper twisted-pair wires with at least two
twists per 307.7 millimeters (12 inches)

?  A maximum of 28.6 ohms dc resistance per 304.8
meters (1000 feet)

?  Impedance characteristics

-       90 to 120 ohms at 256 kHz
-       87 to 117.5 ohms at 512 kHz
-       85 to 114 ohms at 772 kHz
-       84 to 113 ohms at 1000 kHz

?  Maximum attenuation per 304.8 meters (1000 feet)

-       4.00 dB at 256 kHz
-       5.66 dB at 512 kHz
-       6.73 dB at 772 kHz
-       8.00 dB at 1000 kHz

?  In addition, all Type 3 Specified Media must meet
at least one of the following industry specifications:


-       ANSI/ICEA S-80-576-1983
-       REA PE-1
-       Bell System 48007
 
Possible Interference Sources

The network configurations described in this document
have been tested and shown to be operational in
typical office environments. However, these
configurations may not operate satisfactorily in
environments where electrical interference exists. You
must consider those environments exposed to
interference when planning your network configuration.

Telephone twisted-pair cable is unshielded and is
generally not well balanced at high frequencies.
Therefore, this type of wiring is subject to crosstalk
and electrical interference from the following:

?  Intercoms

?  Fluorescent lighting

?  Power cables

?  Arc welding equipment

?  HVAC (heating, ventilation, and air conditioning)
equipment

?  Radio frequency transmissions from commercial
broadcasters and base-station operations

?  Radar installations in the immediate area

?  Electric Motors 

.. In addition, the telephone cable data network must
be contained within a single building. Any cable runs
between buildings are not supported. Network operation
with nonspecified wiring, jacks, plugs, connecting
blocks, or cable run-lengths may be unsatisfactory and
is not recommended or supported.

HTH

Best Regards,

/Paul
--
Paul Tykodi
Principal Consultant
TCS - Tykodi Consulting Services LLC
E-mail: ptykodi@xxxxxxxxxx

>date: Fri, 4 Mar 2005 07:29:28 -0000
>from: "Raby, Steve \(GE Advanced Materials,
>consultant\)" <steve.raby@xxxxxx>
>subject: 6400 Printer problem
>
>Hello All,
>
>I have a problem with some of the 6400 printers I
have >here, they are stuck on Vary on Pending, they
are >connected to the network by a 'balloon', other
>printers on the same controller are working fine. I
>have varied off and on, unplugged from the network,
>switched on and off, I just don't know why the things
>refuse to work.
>
>Steve

=====
Paul Tykodi
Principal Consultant
TCS - Tykodi Consulting Services LLC

Tel/Fax: 603-343-1820
Mobile:  603-866-0712
E-mail:  ptykodi@xxxxxxxxx
WWW:     http://www.tykodi.com


        
                
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