Re: [foxboro] FT FOLAN Faults
- From: "Brian Long" <blong@xxxxxxx>
- To: <foxboro@xxxxxxxxxxxxx>
- Date: Mon, 10 Jun 2002 13:19:01 -0500
Tom,
Both the nodes in question have DNDX cards. In fact Foxboro had me replace
my Rev. E's with Rev. H's. I just changed them today. From past calls to
Foxwatch, traffic rates have not been a problem. But by the time they get
logged in the traffic may be down. I'll let you know what kind of typical
traffic rates I have when I can get the info.
Thanks for the info,
Brian
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx
[mailto:foxboro-bounce@xxxxxxxxxxxxx]On Behalf Of Tom VandeWater
Sent: Saturday, June 08, 2002 12:58 AM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] FT FOLAN Faults
Brian,
I'm curious to know if the nodes that you are having trouble keeping the
CBLAN modules running FT also have nodebus extenders on them? We have seen
the same thing on two of our nodes and both have nodebus extenders. Even
though we also have FT CP's on those nodes, the first FT modules to go none
FT have been the Carrierband modules.
As Alex Johnson correctly stated, these problems can be related to high
traffic. When the modules get so busy passing packets that they don't have
time to perform their FT checks, the Primary gives up on the FT Shadow and
goes on by itself.
But our worst case avg traffic rate on one of our 22 nodes is less than
150 packets per second which is only half of the 300 that Foxboro says they
can sustain. They say the nodebus can handle bursts of 600 PPS. I think
for the most part that is accurate. But when you have a high data
communication rate on an ethernet network you are likely to have more
collisions. The way that nodebus extenders, (either FONBE's or Copper),
respond to collisions by sending out jamming signals, cause an even bigger
communication logjam. The jamming forces nodebus stations to back off and
wait a random amount of time to resume communication. Why the FT CBLANS are
the first to go may be because they are doing both 802.3 (Nodebus) and 802.4
(Tokenbus) communications. But we have seen exactly what you describe.
Conditions can deteriorate enough that FT CP's will shed their partner and
can also cause some stations to switch to the "B" nodebus while others stay
on the "A" nodebus even though there is no Nodebus cable fault reported in
SysMon. That is when things really get ugly and you start to lose data
connections, Cyan on screens, historian data loss, and such.
Again, please let me know if the nodes with CBLAN problems also have
Nodebus Extenders. Thanks!
Tom VandeWater
Dow Corning Corp.
Carrollton, KY
----- Original Message -----
From: "Brian Long" <blong@xxxxxxx>
To: "Foxboro" <foxboro@xxxxxxxxxxxxx>
Sent: Friday, June 07, 2002 2:44 PM
Subject: [foxboro] FT FOLAN Faults
>
> Just wondering if anyone else has recurring problems with fiber optic
fault
> tolerant LAN cards faulting. I have a 6 node system and the part of the
LAN
> I continue to have problems with is the two nodes that are fault tolerant.
> Normally, just the shadow faults. The other four nodes that are single
have
> never been an issue.
>
> Thanks,
> Brian Long
> E&I Superintendent
> Green Bay Packaging
> Arkansas Kraft Division
>
>
>
> _______________________________________________________________________
> This mailing list is neither sponsored nor endorsed by Invensys Process
> Systems (formerly The Foxboro Company). Use the info you obtain here at
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>
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>
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
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_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
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