Wiring on RJ45 wall socket
Pandora
Electric part K5845 - available in UK)
If the pins in the front of the socket are numbered 1-8 left to right,
then the corresponding connections on the IDC block on the rear are
arranged as follows:
4 X X 5
6 X X 3
8 X X 1
7 X X 2
Why is this arrangement used?
I can see how the wires in the pair to terminals 7 and 8 are kept
together, as are the pair to 1 and 2.
But you have to untwist the pair going to terminals 6 and 3, as the
wires in this pair are on opposite sides of the block. You also have
to untwist the pair going to 4 and 5.
If keeping the twist right up to the terminal block is important, why
isn't the IDC block arrangement as follows:
4 X X 6
5 X X 3
8 X X 1
7 X X 2
or am I missing something?
Lurch
mused:
No, you're looking at it too closely, just punch the cables down and
screw the cover on.
--
Regards,
Stuart.
Pandora
I don't know if that ascii depiction of the IDC block is coming out
correctly but the distance between the two columns of four is 15mm,
whereas the distance between pins in each column (e.g. between pins 7
and 8) is 4mm.
DavidM
"Pandora" <no--...@pandora.be> wrote in message
news:1183890123....@q75g2000hsh.googlegroups.com...
http://www.tlc-direct.co.uk/Technical/Networking/Networking.htm
Note that there are two standards for connection (568A and568B). It doesn't
matter which you use, as long as they are the same at both ends!
The arrangement of the wires and pins is all to do with minimising crosstalk
between the wires in the cable.
David
Pandora
> "Pandora" <no--s...@pandora.be> wrote in message
Thanks
I understand about two standards for connection but my question is
about the physical laying of the wires, rather than the colour of the
sheaths.
I wondered why the manufacturer had laid the IDC connectors out that
way and whether I was misunderstanding why two pairs terminated on
opposite side of the terminal block.
Doug McIntyre
>>>I am wiring up some RJ45 network sockets for the first time. (MK
>>> Electric part K5845 - available in UK)
>I wondered why the manufacturer had laid the IDC connectors out that
>way and whether I was misunderstanding why two pairs terminated on
>opposite side of the terminal block.
Because thats the way they did it? Some of Leviton's jacks are that
way too. But they seem to change the layout from model to model.
Its probably cheaper for them to produce the circuit boards with the
wiring like this that matches the way the wires actually are inside
the jack itself.
As long as you can punch down reasonably you should pass certification
no problem, its not like they're going to produce something that won't.
Other manufacturers do it differently.
Personally, I like the Hubbell XJack layout which does keep the pairs
together (and angeled) as far into the connector as they can.
DTC
> I wondered why the manufacturer had laid the IDC connectors out that
> way and whether I was misunderstanding why two pairs terminated on
> opposite side of the terminal block.
Its just simply the way a particular manufacture laid out the printed
circuit board connecting the IDC punch downs to the jack pins. Its not a
critical or important thing to worry about.
A Hubble brand 568B physical layout looks like this:
Gold pin side
Pin 2 Orange/White Pin 8 Brown/White
Pin 1 White/Orange Pin 7 White Brown
Pin 4 Blue/White Pin 6 Green/White
Pin 5 White/Blue Pin 3 White/Green
Here all associated pairs are on the same sides of the jack.
A Leviton brand 568B physical layout looks like this:
Gold pin side
Pin 2 Orange/White Pin 7 White Brown
Pin 1 White/Orange Pin 8 Brown/White
Pin 3 White/Green Pin 6 Green/White
Pin 5 White/Blue Pin 4 Blue/White
With the Leviton, the orange and brown pairs terminate on the same sides of
the jacks, and the blue and green pairs are split on opposite sides of the
jack.
On a side note, an ethernet jack is properly called an 8-pin jack, but us
old timers often still incorrectly call it an RJ45 jack.
JohnW
22g2000hsm.googlegroups.com>, says...
>I am wiring up some RJ45 network sockets for the first time. (MK
> Electric part K5845 - available in UK)
>
> If the pins in the front of the socket are numbered 1-8 left to right,
> then the corresponding connections on the IDC block on the rear are
> arranged as follows:
>
> 4 X X 5
> 6 X X 3
> 8 X X 1
> 7 X X 2
>
> Why is this arrangement used?
>
> I can see how the wires in the pair to terminals 7 and 8 are kept
> together, as are the pair to 1 and 2.
>
> But you have to untwist the pair going to terminals 6 and 3, as the
> wires in this pair are on opposite sides of the block. You also have
> to untwist the pair going to 4 and 5.
>
> If keeping the twist right up to the terminal block is important, why
> isn't the IDC block arrangement as follows:
>
> 4 X X 6
> 5 X X 3
> 8 X X 1
> 7 X X 2
>
> or am I missing something?
>
OK - you got me to go and look at my stock and they are:
6x x5
3x x4
7x x1
8x x2
They aren't MK, so the question arises as to why you are using
data devices made by an electrical company? :-) At least it
explains why we shouldn't automatically accept an installation
done by an electrician :-) Thanks for warning me...
I'd check that the label on your connectors is actually
telling you which pins the PCB is connecting to - it wouldn't
be the first time I've seen pin numbers on labels and even
etched on a PCB being wrong...
You are correct in saying that you shouldn't untwist the wires
more than is absolutely necessary and so they should
preferably be on adjacent connectors of a punch-down. If a
connector doesn't accommodate the "split pair" (3-6) in it's
PCB, I'd find a different make, since it is probably a pre-
100Mbps design.
FYI, some of the first twisted-pair Ethernet installations I
used were wired by a site tech, who hadn't seen them before>
He used the pairs to pins 1-2, 3-4, 5-6 & 7-8. It tested OK
with his cable tracer and 'worked' at 10Mbps but failed at
100Mbps... Guess who had the first 100Mbps device? :-)
--
JohnW.
Replace the obvious with co.uk in 2 places to mail me.
Robert Redelmeier
> On 8 Jul, 11:22, Pandora <no--s...@pandora.be> wrote:
>> If the pins in the front of the socket are numbered 1-8 left to right,
... assuming tab down, this is conventional numbering
>> 4 X X 6
[bl] [gr]
>> 5 X X 3
>>
>> 8 X X 1
[br] [or]
>> 7 X X 2
>>
>
> I don't know if that ascii depiction of the IDC block is coming
> out correctly but the distance between the two columns of
> four is 15mm, whereas the distance between pins in each column
> (e.g. between pins 7 and 8) is 4mm.
This is a nice layout, it minimizes the pair untwist.
Punch down as marked above for T-568-B. For T-568-A,
swap the orange and green pairs. Colors on evens.
-- Robert
Pandora
>
> A Leviton brand 568B physical layout looks like this:
>
> Gold pin side
> Pin 2 Orange/White Pin 7 White Brown
> Pin 1 White/Orange Pin 8 Brown/White
> Pin 3 White/Green Pin 6 Green/White
> Pin 5 White/Blue Pin 4 Blue/White
>
> With the Leviton, the orange and brown pairs terminate on the same sides of
> the jacks, and the blue and green pairs are split on opposite sides of the
> jack.
That's the same as the MK Electric brand. I think that the Hubble
brand layout is better but there you go. (I use MK because the network
sockets match the profile of the power sockets - it's an aesthetic
thing.)
OK, now I know that there's no problem, I'll just wire up as everybody
has suggested.
Thanks, guys.
Owain
> On a side note, an ethernet jack is properly called an 8-pin jack, but
> us old timers often still incorrectly call it an RJ45 jack.
Especially if you're not running Ethernet over it.
Owain
glen herrmannsfeldt
> I am wiring up some RJ45 network sockets for the first time. (MK
> Electric part K5845 - available in UK)
> If the pins in the front of the socket are numbered 1-8 left to right,
> then the corresponding connections on the IDC block on the rear are
> arranged as follows:
> 4 X X 5
>
> 6 X X 3
>
> 8 X X 1
>
> 7 X X 2
>
> Why is this arrangement used?
If it is appropriately Cat5 or Cat6 certified then there is
no reason to worry about the arrangement. I would say it
is a little easier to design for high frequencies if the
two for a pair were closer, but it isn't that hard either way.
Most that I remember have the wires of the pair opposite each other
(like (4,5) and (6,3) in your example) for all pairs. It might
be a little easier to punch down that way.
-- glen
Carl Navarro
All of what you say is true, Glen, but Leviton, and obviously MK,
chose to do it this way. I've used Leviton for several years, and,
with the Rapid Jack tool, it's not so bad to fan the wires and seat
them all at once. The jacks have a lower profile than most and it
fits in a Leviton surface mount housing better than anythng else, so I
keep going back to them.
Carl Navarro
DTC
> All of what you say is true, Glen, but Leviton, and obviously MK,
> chose to do it this way. I've used Leviton for several years, and,
> with the Rapid Jack tool, it's not so bad to fan the wires and seat
> them all at once.
How many jacks did your Rapid Jack Tool do before the cutting blades got
dull and started mashing up the jack? Mine has started damaging the jacks
after only a hundred or so jacks.
Carl Navarro
wrote:
I confess, I only use it for high productivity and that means two jobs
so far for about 160 jacks. I am really careful to seat the jack in
the slot before I crimp it. I don't get it out for one or two jacks.
I have the eversharp 110 blade...and BTW don't drop it on the tile
floor bacause Murphy says it will always fall point first. Especially
when you're in a hurry.
Carl