Re: [foxboro] R: DNBI Cabling for long Distance

DNBXs? NOOOOOOOOOOOOOOOOOOooooooooooooooooo.............................. 
:)

We replaced the DNBXs in one plant here with the remote 1x8/NCNI setup 
after they caused several system-wide smurfing issues.  What we found out 
from this was:


1. DNBXs aren't the best solution for remote WPs.  While our collective 
gut determined this fairly quickly, it took awhile for us to find someone 
in Foxboro to back that assertion up.


2. The "classic" nodebus itself isn't a great design.  Having two physical 
cables buys you little in a failure situation that causes any kind of 
noise.  Foxboro only tacitly admits this in telling you to upgrade to 
v8/mesh.


3.  Few people in Foxboro really know how the nodebus works.  Or maybe 
they know, but can't explain it.  I hope that situation is better with the 
mesh setup.


Corey Clingo
BASF Corporation






"Crivellotto, Davide" <Davide.Crivellotto@xxxxxxxxxxxxxxxx> 
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[foxboro] R: DNBI Cabling for long Distance






Another solution is to use DNBX instead of DNBI, BUT I was told about
Nodebus problems with this configuration.

I think NCNI and a remote 1x8 will be good.

Davide

-----Messaggio originale-----
Da: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
Per conto di Corey R Clingo
Inviato: Tuesday, July 25, 2006 4:07 PM
A: foxboro@xxxxxxxxxxxxx
Oggetto: Re: [foxboro] DNBI Cabling for long Distance

I'd be careful with that.  The additional latency of the converters may=20
exceed the maximum allowed propagation time on the nodebus segment,=20
causing problems with the Ethernet collision detection,

When we have had to do this, we dropped in a remote 1x8  and used FONBEs

(in the old days).  or NCNIs (now).  If you just need to connect two or=20
three segments you can connect the NCNIs back-to-back without a switch.


Corey Clingo
BASF Corporation






"Khudhair, Waleed K" <waleed.khudhair@xxxxxxxxxx>=20
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07/25/2006 06:01 AM
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[foxboro] DNBI Cabling for long Distance






Guys,
As per the I/A Doc's, the DNBI can be cabled in either of two
configurations:

*       Local - where the DNBI and the processor share the same
enclosure

*       Medium-Distance - where the DNBI and the processor are separated
by a distance of greater than 2 m (6 ft) up to 45m (150 ft).

What about if the DNBI and the processor are separated by a distance of
greater than 45m, can we use a media converter at both ends and use
fiber optic cables in between?

Regards,

_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
Waleed K. Al-Khudhair
Uthmaniyah Gas Plant
Engineering Building
Room 130
DCS Administrator
Tele   +9663577-5396
Pager +9663870-1474
eFax   +96638744444 / Ext. 133732





 
 
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