RJ Jack Glossary
Here's a description of all RJ jacks from RJ11 to RJ48
1.
RJ-11C and RJ-11W: Are normally associated with single-line ancillary devices,
telephone sets, or -9 dBm (permissive) modems and provide bridged connections to
the tip and ring of a telephone line. RJ-1 1 C is surface or flush-mounted for
use with desk telephone sets, while RJ-1 1 W is used for wall mounted telephone
sets.
2.
RJ-17C: Provides a single-line bridged connection of tip and ring to special
telephone sets or ancillary equipment (e.g., ECG machines) in hospital
critical-care areas. Only registered equipment conforming to Article 517 of the
1978 National Electrical Code is permitted to connect to this jack arrangement.
This jack differs from the RJ-1 1 C in that tip and ring appear on pins 1 &
6 rather than 3 & 4.
3.
RJ-12C and RJ-12W: Are normally associated with one line of a key telephone
system, they provide a bridged connection to the tip and ring of the telephone
line and to key system A and Al leads. The tip and ring conductors in the jack
are connected ahead of the key telephone-system line circuit. The RJ-1 2C is
surface- or flush mounted for use with desk telephone sets while the RJ-1 2W is
for wall mounted telephone sets. Typically, these arrangements are used when
registered ancillary equipment must respond to central office or PBX ringing.
4.
RJ-13C and RJ-13W: Are normally associated with one line of a key telephone
system. They provide a bridged connection electrically behind the key-system
line circuit to the tip, ring conductors, and to the A and Al leads. The RJ-13C
is surface- or flush mounted for use with desk telephone sets while RJ-1 3W is
for wall mounted telephone sets. These arrangements are generally used when the
registered ancillary equipment does not require central office or PBX ringing to
function properly.
5.
RJ-14C and RJ-14W: Provide for bridged connections to the tip and ring
conductors of two separate telephone lines. The RJ-1 4C is surface- or flush
mounted for use with desk telephone sets while the RJ-1 4W is for wall mounted
telephone sets.
6.
RJ-16X: Provides a single-line bridged tip and ring and is associated with -9
dBm (permissive) data arrangements that require mode indication for use with
exclusion key telephone sets. The exclusion key telephone set requires a series
jack, RJ-36X (described under 8-position jacks) as its normal means of
connection.
7.
RJ-18C: Provides a bridged connection of single-line tip and ring with make-busy
leads M13 and IVIB1. When the registered equipment provides a contact closure
between the MB and MB1 leads, a make-busy indication is transmitted to the
network equipment busying out the line from further incoming calls. It's
recommended that the busy indication (contact closure) be provided while the
line is in the idle state in order to reduce the possibility of interfering with
a call that is in the ringing or talking state. The RJ-1 EIC is surface- or
flush mounted for use with desk telephone sets.
8.
RJ-19C: Is normally associated with one line of a key telephone system. It
provides a bridged connection of single- line tip and ring behind a key-system
line circuit, with A and Al lead control, and a direct connection for MB/MB1
make- busy leads. When the modem provides a contact closure between the M13 and
MB1 leads, a make-busy indication is transmitted to the network equipment
busying out the line from further incoming calls. It's recommended that the busy
indication (contact closure) be provided while the line is in the idle state in
order to reduce the possibility of interfering with a call that is in the
ringing or talking state. The RJ-1 9C is surface- or flush mounted for use with
desk telephone sets.
9. RJ-25C:
Provides for bridged connection to the tip and ring conductors of three separate
telephone lines. The telephone company will wire the lines to the jack in the
sequence designated by the customer. The RJ-25C is surface- or flush mounted for
use with the desk telephone sets and ancillary devices.
10. RJ-15C:
Is a weatherproof jack arranged to provide single-line bridged connection to tip
and ring. Jack RJ-1 5C can be arranged for surface- or flush mounting depending
upon customer needs.
11.
RJ-AlX / RJ-A3X: Are adapters used to adapt 4 and 12 position jacks,
respectively, to a 6-position miniature bridged jack. They provide bridged
connections to the tip and ring of the telephone line. If A and Al leads are
already terminated in the 4- or 12-pin jack, they will appear in positions 2 and
5 in the adapter. If A and Al leads are not involved, positions 2 and 5 are
reserved for telephone company use.
*RJ-A2X: Is an adapter that
converts a single miniature jack to two miniature jacks. It provides a bridged
connection to the tip and ring conductors of the telephone line. If A and Al
leads are already terminated in an existing miniature bridged jack, they will
appear in positions 2 and 5 in both miniature bridged jacks in the adapters. If
A and Al leads are not provided, positions 2 and 5 are reserved for telephone
company use.
12.
RJ-21X: Provides bridged connections to tip and ring conductors of up to
25 telephone lines. The RJ-21 X is typically used with Traffic-Data Recording
Equipment and Multiple-Line Communications Systems. The user must specify the
connection sequence for each title appearing in the jack.
13.
RJ-22X: Can be associated with a telephone company provided key telephone system
when connection to several lines is required. It provides bridged connections of
up to 12 telephone lines and their associated A and Al leads. The tip and ring
conductors in the jack are wired ahead of the line circuit in the key telephone
system. This arrangement is used when the modem must respond to central office
or PBX ringing.
14.
RJ-23X: Is normally associated with a telephone company provided key telephone
system when connection is required to several lines. It's wired to provide
bridged connections of up to 12 key-system line circuits and associated A and Al
leads. It differs from and is preferred over the RJ-22X, in that tip and ring
conductors in the jack are wired behind the key- system line circuits. This
arrangement is typically used when the modem doesn't require central office or
PBX ringing to function properly.
15.
RJ-24X: Is normally associated with a telephone company provided key
telephone system. It's typically used with registered ancillary devices such as
conferencing devices, music on hold, etc., and is wired to provide the same tip,
ring, A, and Al appearances as a standard five-line key telephone set.
16.
RJ-26X: Is a multiple-line universal data jack for up to 8 lines in a
50-position miniature ribbon connector and accommodates either fixed-loss loop (FLIL)
or programmed (P) types of data equipment. A switch, accessible to the customer,
is provided on each line to select FILL or P type of operation. FLL equipment
transmits at -4 + I dB with respect to one milliwatt and a pad is included in
the data jack so that pad loss plus loop loss is nominally 8 dB. Programmed-type
data equipment adjusts its output power in accordance with a programming
resistor in the data jack. By these means, signals from either FILL or P types
of registered data equipment will arrive at the local telephone company central
office at a nominal -12 dB with respect to one milliwatt for optimum data
transmission.
*RJ-27X: Is a multiple-line
programmable data jack for up to 8 lines in a 50-position miniature ribbon
connector and accommodates programmed data equipment only.
17.
RJ-71C: Provides a multiple series arrangement of tip and ring. It's
typically used with registered series devices such as toll restrictors, etc.
Jack RJ-71 C can accommodate up to 12 circuits per jack (i.e., one tip and ring
"in" and one tip and ring "out," 4 leads per circuit). This
arrangement does not currently provide restoration upon disconnection of
registered equipment. Thus, a manual bridging plug is provided in order to
maintain circuit continuity upon withdrawal of a registered plug.
18.
RJ-31X: Provides a series connection to the tip and ring conductors of a
telephone line. It's wired ahead of all station equipment electrically and is
typically used with registered alarm-reporting devices. When there's an alarm
condition, the registered device functions to cut off all station equipment
wired behind it, via this jack.
19.
RJ-32X: Provides a series connection to the tip and ring conductors of a
telephone line. It differs from RJ-31X in that it's wired ahead of a particular
telephone set rather than ahead of all the station equipment. It's typically
used with registered automatic dialers.
20.
RJ-33X: Is normally associated with a key telephone system. It provides a
series connection to the tip and ring conductors of the telephone line and the
key-system line circuit A and Al leads. The tip and ring conductors are wired
ahead of the key-system line circuit. This arrangement is typically used when
the modem requires central office or PBX ringing.
21.
RJ-34X: Is normally associated with a key telephone system. It's wired to
provide a series connection to the key-system line circuit tip and ring
conductors and its A and Al leads. It differs from RJ-33X in that all conductors
are wired behind the key- system line circuit. This arrangement is typically
used when the modem is not critical as to type of ringing signal or doesn't
require central office or PBX ringing.
22.
RJ-35X: Is normally associated with a key telephone set. It's wired to
provide a series connection to the tip and ring conductors of the telephone line
and a bridged connection to the A and Al leads. It differs from RJ-33X and
RJ-34X in that the tip and ring leads are connected to the common wiring behind
the pickup keys of the station set but ahead of the switch hook. The jack is
wired to the key telephone set so that the modem functions on the line selected
on the key telephone set.
23.
RJ-36X: Provides a connection for a registered telephone set equipped
with an exclusion key when the telephone line is also to be used with a
registered data set or registered protective circuitry. It's wired to provide a
series connection to the tip and ring conductors of the telephone line and mode-
indication leads MI and MIC. With this jack, the exclusion key can be used to
transfer the telephone line between the modem and the telephone set. As a
customer option, the exclusion key may be wired so that either the telephone set
or the modem controls the line. In the former case, the exclusion key must be
operated to transfer the telephone line to the modem. In the latter case, the
telephone line is normally associated with the modem. Operation of the exclusion
key is required to transfer the line to the telephone set. In either case, a
closure on the MI and MIC leads indicates the voice mode.
24.
RJ-37X: Is used for providing two-line service with exclusion. The jack
is wired to provide a bridged connection to the tip and ring conductors of two
telephone lines with exclusion on line 1.
25.
RJ-38X: Provides a series connection to the tip and ring conductors of a
telephone line identical to those described for RJ-31X. However, the jack also
provides a continuity circuit which is used as an indication that the plug of
the registered equipment is engaged with the jack. The jack is wired ahead of
all station equipment electrically and is typically used with registered alarm
dialers.
26.
RJ-41 S: Is a single-line universal data jack normally associated with
fixed-loss loop (FLL) or programmed (P) modems. A switch, accessible to the
user, is provided to select FLL to P type of operation. (FLL equipment transmits
at -4 dB with respect to one milliwatt, and a pad is included in the data jack
so that pad loss plus loop loss is nominally 8 dB. Programmed modems adjust
their output power in accordance with a programming resistor in the data jack.
By these means, signals from either FLL or P types of registered modems will
arrive at the local telephone company central office at a nominal -12 dB with
respect to one milliwatt for optimum data transmission.) A sliding cover is
provided to keep dirt and dust from entering the jack when it's not in use. The
FLL /P switch selects the desired method of operation. Two matted surfaces are
provided on the housing of the jack for the telephone company installer to write
in the loop loss (designated LPQ and the telephone line number (designated TLN).
* RJ-45S: Is a single-line
data jack normally associated with programmed (P) modems. This jack is the same
as the universal data jack RJ-41 S described above, except that the pad for
fixed loss loop (FLL) equipment and the switch to select FLL or P type of
operation are omitted. Its appearance is the same as RJ-41 S except that RJ-45S
does not have the FLL /P switch. Both jacks provide bridged connections to the
tip and ring of a telephone line and provide mode-indication leads for use with
exclusion key telephone sets when required. The exclusion key telephone set
requires a series jack RJ-36X as its normal means of connection.
* RJ-41 M and RJ-45M:
Provide a multiple-mounting arrangement for mounting a number of RJ-41S or
RJ-45S Single-Line Universal or Programmed data jacks. The tele- phone companies
will terminate USOCs, RJ-41 M, and RJ-45M with RKM2X (which is the USOC
equivalent for a mounting arrangement) and the appropriate number of RJ-41 S or
RJ-45S single-line data jacks as required by the user. The mounting arrangement
will accommodate up to 16 single-line data jacks. In effect, this arrangement
provides the features of a patch panel. The user has complete flexibility in
patching the color and plug from any modem to any line. The arrangement can be
mounted on a wall or on 19- or 23-inch relay racks.
27.
RJ-48S: Normally associated with DDS services from the telephone company this
jack is used with DDS CSU/DSUs.
*RJ-48C: Normally associated with a DSX-1 Interface for a T1 circuit this jack is used with T1 channel banks, T1 CSU/DSUs.