Part of the problem

[Strathead]

unless they are not electrically/mechanically minded at all, they likely realize each conductor has a proper location to land, I think it is less likely they will know they should maintain twist as much as possible, even some that do a fair amount of electrical work likely don't realize this or why.

you can get away with not maintaining the twist and other things they don't recommend, but it potentially lessens max data speeds. A wrong termination position leaves it not working at all most the time.

My understanding (I'm a hack) is that the lack of twists causes errors in the ones and zeroes. There are always errors but the actual twist of the wires is done to minimize these. The more errors the "slower " the data. Many here are more knowledgeable than me on this, so please chime in if I am incorrect, or inaccurate.

 

[kwired]

My understanding (I'm a hack) is that the lack of twists causes errors in the ones and zeroes. There are always errors but the actual twist of the wires is done to minimize these. The more errors the "slower " the data. Many here are more knowledgeable than me on this, so please chime in if I am incorrect, or inaccurate.

I think you mostly on right track, but the twist rates are mostly because of effects over the length of run.

Every time you transition from say a patch cord to "premises wire" you probably introduce potential losses that are higher in that short distance than within same distance in undisturbed cable. Therefore I believe it is plausible you could have less loss in one poorly done termination than in a run with many well done terminations. Those losses don't mean it won't work but in order for it to work it may need to operate at a lower speed.

 

[LarryFine]

My understanding (I'm a hack) is that the lack of twists causes errors in the ones and zeroes. There are always errors but the actual twist of the wires is done to minimize these. The more errors the "slower " the data. Many here are more knowledgeable than me on this, so please chime in if I am incorrect, or inaccurate.

From two different threads:

The purpose of twisting is to assure that both conductors will pick up any nearby interference (common mode), so the receiving end (differential amplifier - common-mode noise rejection) can ignore it, and pass only the difference signals. The greater the number of twists per inch, the higher the frequency (shorter wavelength) both conductors will pick up equally.


Twisted-pair works by assuring that both wires pick up the interfering signal (called common-mode noise), so it can be ignored by the differential amplifier at the receiving end (called common-mode noise-rejection).

The difference signal is passed through, while any signal common to both wires is rejected, or filtered out. The greater the number of twists per inch, the higher the frequency of interference you can assure will be ignored.

 

[tallgirl]

That's presuming the same component is being installed at both ends.

What about, say, from jacks like above to a patch panel or a plug?

Yeah, that wouldn't work at all. Not even the interior pairs, which is where auto-negotiation is performed.

 

[tallgirl]

I think you mostly on right track, but the twist rates are mostly because of effects over the length of run.

Every time you transition from say a patch cord to "premises wire" you probably introduce potential losses that are higher in that short distance than within same distance in undisturbed cable. Therefore I believe it is plausible you could have less loss in one poorly done termination than in a run with many well done terminations. Those losses don't mean it won't work but in order for it to work it may need to operate at a lower speed.

The advertisements may work, since they are performed using 10Base-T bit rates and encoding. The most likely outcome, if transmission works, will be excessive packet loss. Oddly enough, since 1000Base-T requires that pairs 3 and 4 work, if both ends accept 1000Base-T they'll negotiate 1Gb/s then fail spectacularly. It's one of the maddening things about Ethernet.

 

[Amps]

I'm not convinced of that. I knew people who'd just start with some color pair and go from one end to the next, then wire the other end the exact same way. They'd get the outside pairs right, and that would be it. But, there'd be continuity from pins 1 to 8 on each end.

Split pairs are a no no. Continuity may test pin to pin on each end, but if the pairs are not on their TIA/EIA standard, they will be "split" causing crosstalk issues.

 

[kwired]

Split pairs are a no no. Continuity may test pin to pin on each end, but if the pairs are not on their TIA/EIA standard, they will be "split" causing crosstalk issues.

And this is potentially a bigger problem for a 500 foot run than it is for a 2 foot patch cord.

 

[Amps]

And this is potentially a bigger problem for a 500 foot run than it is for a 2 foot patch cord.

Yeah, especially when Ethernet has a distance limitation of 100 meters or 328 ft. At 500 ft attenuation may be an issue and the receiver's have trouble distinguishing bit transitions.

 

[kwired]

Yeah, especially when Ethernet has a distance limitation of 100 meters or 328 ft. At 500 ft attenuation may be an issue and the receiver's have trouble distinguishing bit transitions.

OK my bad there but my point is bad twist in a short patch cord may not be much of a problem vs same bad twist for entire max length run it is intended to be used for.

 

[Amps]

OK my bad there but my point is bad twist in a short patch cord may not be much of a problem vs same bad twist for entire max length run it is intended to be used for.

Didn't mean to critique. I see what you meant. Just pointing out about possible attenuation if it really were 500ft.

 

[brantmacga]

A couple of Saturday’s ago, I traveled to visit the mill where some of my corn goes to be processed. It’s a 10-story tall building, separates the germ, corn flake sorting, etc. It’s pretty big. I asked the owner how many people staffed it during the week. He said, “I run this from my cell phone.” Couldn’t believe it. He does have a couple of people there during the week though. He gets alerts from the plant when anything is out of spec.


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[Amps]

A couple of Saturday’s ago, I traveled to visit the mill where some of my corn goes to be processed. It’s a 10-story tall building, separates the germ, corn flake sorting, etc. It’s pretty big. I asked the owner how many people staffed it during the week. He said, “I run this from my cell phone.” Couldn’t believe it. He does have a couple of people there during the week though. He gets alerts from the plant when anything is out of spec.


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That is cool.

 

[ptonsparky]

A couple of Saturday’s ago, I traveled to visit the mill where some of my corn goes to be processed. It’s a 10-story tall building, separates the germ, corn flake sorting, etc. It’s pretty big. I asked the owner how many people staffed it during the week. He said, “I run this from my cell phone.” Couldn’t believe it. He does have a couple of people there during the week though. He gets alerts from the plant when anything is out of spec.


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Nice. Would have been interesting to set up.

 

[Amps]

Nice. Would have been interesting to set up.

I was thinking that too. Hope it has good security from hacking!