|
Straight
/ Rollover / Crossover cables
Below you can
find the wiring schemes of the straight, rollover and crossover
cables.
|
Pin
no.
|
Pair
no.
|
Function
|
Wire
Color
|
Used
with 10/100 Base-T Ethernet?
|
Used
with 100 Base-T4 and 1000 Base-T Ethernet?
|
|
1
|
2
|
Transmit |
White/Orange |
Yes
|
Yes
|
|
2
|
2
|
Receive |
Orange/White |
Yes
|
Yes
|
|
3
|
3
|
Transmit |
White/Green |
Yes
|
Yes
|
|
4
|
1
|
Not
used |
Blue/White |
No
|
Yes
|
|
5
|
1
|
Not
used |
White/Blue |
No
|
Yes
|
|
6
|
3
|
Receive |
Green/White |
Yes
|
Yes
|
|
7
|
4
|
Not
used |
White/Brown |
No
|
Yes
|
|
8
|
4
|
Not
used |
Brown/White |
No
|
Yes
|
Straight
through cable T568-B cable standard (AT&T specification)
|
Router
or switch console port (DTE)
|
RJ-45
to RJ-45 Rollover Cable
(one end)
|
RJ-45
to RJ-45 Rollover Cable
(other end)
|
RJ-45
to DB9
Adapter
|
Console
Device (PC workstation serial port)
|
|
RTS
|
1
|
8
|
8
|
CTS
|
|
DTR
|
2
|
7
|
6
|
DSR
|
|
TxD
|
3
|
6
|
2
|
RxD
|
|
GND
|
4
|
5
|
5
|
GND
|
|
GND
|
5
|
4
|
5
|
GND
|
|
RxD
|
6
|
3
|
3
|
TxD
|
|
DSR
|
7
|
2
|
4
|
DTR
|
|
CTS
|
8
|
1
|
7
|
RTS
|
Rollover
Console Cable
RTS = Request To Send, DTR = Data
Terminal Ready, TxD = Transmit Data, GND = Ground (One for TxD
and one for RxD),
RxD = Receive Data, DSR = Data Set Ready, CTS = Clear To Send.
|
Pin
no.
|
Pair
no.
|
Function
|
Wire
Color
|
Used
with 10/100 Base-T Ethernet?
|
Used
with 100 Base-T4 and 1000 Base-T Ethernet?
|
|
1
|
3
|
Transmit |
White/Green |
Yes
|
Yes
|
|
2
|
3
|
Receive |
Green/White |
Yes
|
Yes
|
|
3
|
2
|
Transmit |
White/Orange |
Yes
|
Yes
|
|
4
|
1
|
Not
used |
Blue/White |
No
|
Yes
|
|
5
|
1
|
Not
used |
White/Blue |
No
|
Yes
|
|
6
|
2
|
Receive |
Orange/White |
Yes
|
Yes
|
|
7
|
4
|
Not
used |
White/Brown |
No
|
Yes
|
|
8
|
4
|
Not
used |
Brown/White |
No
|
Yes
|
Straight
through cable T568-A cable standard
To
build a crossover cable you have to wire one end to the T568-A standard
and the other one to T568-B standard.
The
main disadvantage of UTP is that it is more prone to electrical
noise than other types of media. It can only be run for 100 m (325
ft) without the signal being deteriorated below accepted standards.
However, because it's the least expensive, is thin and easy to install,
and capable of reaching high speeds, it remains the most used cable
type.
You've noticed that I said earlier the UTP could only be 100 m long
for the signal to recognizable. Of course, you want your LAN to
be wider than that. This is where repeaters step in :) A repeater
is a device that can regenerate the signal so that you can extend
the dimensions of the net. A multi-port repeater is called a hub,
a crucial element in an Ethernet LAN.
Another kind
of copper cable is STP (Shielded Twisted Pair). This is much like
the UTP with the difference that the pairs are protected from EMI
and RFI by a metallic foil that acts like a shield. This shielding
also supports the cable's weight. Of course, all this benefits show
up in the cost of the cable, which is higher than UTP's. |
05:56 
Tagan TG480-U01 480W ATX / EPS Power Supply Review 
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