Michael said:
Do you even know what a REAL RJ45 is? The connectors are actually
8P8C modular plugs and jacks. RJ45 is only one application for that
configuration, and there are a number of modified 8P8C connectors with
different keys to prevent them from being used in other jacks. When you
work in manufacturing or design, you HAVE to make sure that you're
buying the right parts for the job.
Here is a hint: RJ means "Registered Jack", which is a telephone
industry standard for telephone wiring, not computer networking.
Common types
* RJ11C/RJ11W: 6P2C, for one telephone line (6P4C with power on
second pair)
* RJ14C/RJ14W: 6P4C, for two telephone lines
* RJ25C/RJ25W: 6P6C, for three telephone lines
Uncommon types
* RJ12C/RJ12W: 6P4C, for one telephone line ahead of the key system
* RJ13C/RJ13W: 6P4C, for one telephone line behind the key system
* RJ15C: 3-pin weatherproof, for one telephone line
* RJ18C/RJ18W : 6P6C, for one telephone line with make-busy arrangement
* RJ61X: 8P8C, for four telephone lines
* RJ21X: 50-pin miniature ribbon connector, for up to 25 lines
* RJ2MB: 50-pin miniature ribbon connector, 2-12 telephone lines
with make-busy
* RJ31X: 8P8C (although usually only 4C are used), allows an alarm
system to seize the telephone line to make an outgoing call during an
alarm. Jack is placed ahead of all other equipment.
* RJ38X: 8P8C, similar to RJ31X, with continuity circuit
* RJ41S: 8P8C keyed, for one data line, universal
* RJ26X: 50-pin miniature ribbon connector, for multiple data lines,
universal
* RJ27X: 50-pin miniature ribbon connector, for multiple data lines,
programmed
* RJ48S: 8P8C, for four-wire data line (DDS)
* RJ48C: 8P8C, for four-wire data line (DSX-1)
* RJ48X: 8P8C with shorting bar, for four-wire data line (DS1)
* RJ49C: 8P8C, for ISDN BRI via NT1
* RJ71C: 12 line series connection using 50 pin connector (with
bridging adapter) ahead of customer equipment. Mostly used for call
sequencer equipment.
* RJ45S: 8P2C + keyed, for one data line with programming resistor
"Unofficial" (incorrect) plug names
These "RJ" names do not really refer to truly existing FCC RJ types:
* "RJ9", "RJ10", "RJ22": 4P4C or 4P2C, for telephone handsets. Since
telephone handsets do not connect directly to the public network, they
have no Registered Jack code whatsoever.
* "RJ45": 8P8C, informal designation for T568A/T568B, including
Ethernet; not the same as the true RJ45/RJ45S
* "RJ50": 10P10C, for data
DB connector
A family of plugs and sockets widely used in communications and computer
devices. DB connectors come in 9, 15, 25, 37 and 50-pin sizes. The DB
connector defines the physical structure of the connector, not the
purpose of each line.
D-subminiature connectors were invented by ITT Cannon , part of ITT.
Cannon's part-numbering system uses a D as the prefix for the whole
series, followed by a letter denoting the shell size (A=15 pin, B=25
pin, C=37 pin, D=50 pin, E=9 pin), followed by the actual number of
pins, followed by the gender (M=male, F=female). For example, DB25M
denotes a D-sub with a 25-pin shell size and 25 male contacts. The pins
in these connectors are spaced approximately 0.108 inch (2.74 mm) apart
with the rows spaced 0.112 inch (2.84 mm) apart.
There are now D-sub connectors which have the original shell sizes, but
more pins, and the names follow the same pattern. For example, the DE15,
usually found in VGA cables, has 15 pins in a shell the same size as a
DE9. The full list of connectors with this pin spacing is: DE15, DA26,
DB44, DC62, and DD78. Alternatively, following the same confusion
mentioned above in which all D-sub connectors are called "DB", these
connectors are often called DB15HD, DB26HD, DB44HD, DC62HD, and DD78HD,
where the "HD" stands for "high density". They all have 3 rows of pins,
except the DD78, which has 4.
A series of D-sub connectors with even denser pins is called "double
density", and consists of DE19, DA31, DB52, DC79, and DD100. They have 4
rows of pins.
There is yet another similar family of connectors that is easy to
confuse with the D-sub family, but is not part of it. These connectors
are named like "HD50" and "HD68", and have a D-shaped shell but the
shell is about half the width of a DB25. They are common in SCSI
attachments.