Ethernet Cable Woes - On and Off every second
Bookmark this page:
 Yahoo!
 Google
 Windows Live
 del.icio.us
 digg
 Netscape
|
|
||||||||||||||||||||||||||||||||||
|
Posted by glen herrmannsfeldt on February 20, 2007, 3:17 pm
Please log in for more thread options Al Dykes wrote: (snip) Someone did post here in the past about running ethernet through an arc welding factory. While I agree that electrical interference doesn't seem likely, there might be some possibility of mechanical effects, such as vibration on a loose contact. I still have not gotten around to testing 240VAC common mode voltage on UTP ethernet to prove that it actually works. I probably have enough disposable ethernet parts to do it. -- glen | ||||||||||||||||||||||||||||||||||
|
Posted by Al Dykes on February 20, 2007, 3:32 pm
Please log in for more thread options >Al Dykes wrote:
> >(snip) > >> For properly wired cable, IMO, You'd have to be working right next to
>> welding or high-power radio equipment to even *think* about >> interference. >
>Someone did post here in the past about running ethernet through >an arc welding factory. > >While I agree that electrical interference doesn't seem likely, >there might be some possibility of mechanical effects, such as >vibration on a loose contact. > >I still have not gotten around to testing 240VAC common mode >voltage on UTP ethernet to prove that it actually works. >I probably have enough disposable ethernet parts to do it. > All RJ45 ethernet connections are electrically isolated to (ISTR) 4,000V via coupling transformers. It's part of the spec. You should be perfectly safe :-) Let us know how it turns out. When UTP was new there was a paper published that described the attempts made to induce errors in a UTP Ethernet connection. Copious amounts of cable was wrapped around welders, fluorescent lights, Microwave ovens, and Xerox copiers while BERT tests were run. The error rate was essentially zero. Over the years, UTP cable has only gotten better in it's ability to reject induced energy. -- a d y k e s @ p a n i x . c o m Don't blame me. I voted for Gore. A Proud signature since 2001 | ||||||||||||||||||||||||||||||||||
|
Posted by glen herrmannsfeldt on February 21, 2007, 5:44 pm
Please log in for more thread options
Al Dykes wrote: (I wrote) >>I still have not gotten around to testing 240VAC common mode
>>voltage on UTP ethernet to prove that it actually works. >>I probably have enough disposable ethernet parts to do it. > All RJ45 ethernet connections are electrically isolated to (ISTR)
> 4,000V via coupling transformers. It's part of the spec. > You should be perfectly safe :-) Let us know how it turns out.
Safe, but it will be nice to see that it still works, too. That depends some on getting it only as a common mode voltage, which would be easy with center tapped transformers, but they don't usually use them. > When UTP was new there was a paper published that described the
> attempts made to induce errors in a UTP Ethernet connection. Copious > amounts of cable was wrapped around welders, fluorescent lights, > Microwave ovens, and Xerox copiers while BERT tests were run. The > error rate was essentially zero. That is what I expect, but sometime I wanted to try it. I think I have a transformer up to 208V, so I might only get that high. -- glen | ||||||||||||||||||||||||||||||||||
|
Posted by Dmitri(Cabling-Design.com on February 27, 2007, 12:37 pm
Please log in for more thread options
Al Dykes wrote: > For properly wired cable, IMO, You'd have to be working right next to
> welding or high-power radio equipment to even *think* about > interference. > How do you know the "once a second" bit?
I agree with Al. These cables and associated equipment are usually pretty resilient to interference. I think you should look into simpler issues with the network configuration. There may be couple devices with the same IP address on the same subnet or the equipment is trying to re-negotiate speed or duplex mode or a similar networking related issue and not the cable. Especially considering the regularity of the problem. Interference issues tend to be random except of course when the source of EMI is switched on and off regularly itself. -- Best Regards, Dmitri Abaimov, RCDD http://www.cabling-design.com/ Home Cabling Guide, Cabling Forum, color codes, pinouts and other useful resources for premises cabling users and pros -- +--------------------------------------------------------------------+ | http://forums.cabling-design.com/ | | *** a better way to USENET *** | | no-spam Web and RSS interface to your favorite newsgroup | | 24hoursupport.helpdesk,comp.dcom.cabling - messages and counting! | +--------------------------------------------------------------------+ | ||||||||||||||||||||||||||||||||||
|
Posted by Al Dykes on February 27, 2007, 1:45 pm
Please log in for more thread options
>Al Dykes wrote:
> > >> For properly wired cable, IMO, You'd have to be working right next to
>> welding or high-power radio equipment to even *think* about >> interference. >
>> How do you know the "once a second" bit?
>
>I agree with Al. These cables and associated equipment are usually pretty >resilient to interference. I think you should look into simpler issues >with the network configuration. There may be couple devices with the same >IP address on the same subnet or the equipment is trying to re-negotiate >speed or duplex mode or a similar networking related issue and not the >cable. Especially considering the regularity of the problem. Interference >issues tend to be random except of course when the source of EMI is >switched on and off regularly itself. I still want to know ow the OP determined the "once a second" bit. -- a d y k e s @ p a n i x . c o m Don't blame me. I voted for Gore. A Proud signature since 2001 | ||||||||||||||||||||||||||||||||||
| Similar Threads | Posted |
| Ethernet Cable Woes - On and Off every second | February 19, 2007, 8:20 pm |
| Ethernet cable shield | November 23, 2004, 5:02 pm |
| Firewire using on existing Ethernet cable | August 6, 2005, 7:36 am |
| Cable over ethernet for two Wireless access points | July 23, 2004, 6:57 pm |
| CAT-5 cable stuck in ethernet port - can't remove | April 26, 2006, 5:49 am |
| Re: Ethernet connection sensitive to cable length | May 3, 2008, 12:37 pm |
| DIY Ethernet | September 10, 2004, 8:57 pm |
| Ethernet cabling used outside | July 29, 2004, 7:57 pm |
| Cat 5 for phone and ethernet? | December 20, 2004, 9:57 pm |
| Cat 5 for phone and ethernet? | December 20, 2004, 9:56 pm |
| PoE and Ethernet switches | October 1, 2005, 10:22 am |
| Re: ethernet polarity | November 4, 2005, 10:44 pm |
| Cat 5e vs 6 and gigabit ethernet | February 4, 2006, 1:12 am |
| Re: ethernet and AC in same conduit | January 2, 2009, 8:47 pm |
| Gigabit Ethernet Cabling | November 17, 2004, 3:55 pm |
> welding or high-power radio equipment to even *think* about
> interference.