RJ Connector

The Registered Jack (RJ) is a connector specifically designed for networking applications. The standard defines only the wiring pattern of the connector, not the geometry or gender. The term ‘Jack’ refers to the female connector even though the standard does not differentiate the gender of the connector. These connectors are also referred to as “modular connectors” as they were helpful in making the telephone network of early days more modular. The RJ standard is primarily defined for the wiring of telephone networks. The connectors following RJ standard wiring pattern are called RJ connector and are available in both male and female types. There is large number of RJ standard connectors available like, RJ11, RJ14, RJ21, RJ45 etc.

Image of a RJ standard female connector

Fig. 1: Image of a RJ standard female connector

Image of a RJ standard male connector

Fig. 2: Image of a RJ standard male connector

The modular connectors are commonly identified by their ‘contact’ number and their ‘position’ number. The number of contacts refers to the total number of pins in the connector and the number of positions refers to the total number of positions available in which the contacts can be installed in a connector. The number of positions of a connector hence indirectly refers to the actual size of a connector. The modular connectors are defined in four basic sizes, four, six, eight and ten. The 6 position connector with 4 contacts is called 6P4C and an 8 pin connector with 8 contacts is called 8P8C and so on.

Now let us take a look at some of the commonly found RJ connector, their applications and pin-outs.

The pin position of female modular connector from 4 positions to 10 positions is shown in the following figure.

Image showing pin positions in female modular connectors

Fig. 3:Image showing pin positions in female modular connectors

RJ11 Connector

RJ11

The RJ11 standard connectors use a 6P2C, 6 position 2 contact modular connector. They are very commonly used as telephone cable connectors. It can be also used as connector to dial-up modem which can operate up to 56 Kbps data speed.

Image of Male and Female RJ11 connector

Fig. 4: Image of Male and Female RJ11 connector

The pin-out of the 6P2C connector as RJ11

PIN 1 ——————à Absent

PIN 2 ——————à Absent

PIN 3 ——————à R1

PIN 4 ——————à T1

PIN 5 ——————à Absent

PIN 6 ——————à Absent

RJ 14 Connector

RJ14

The RJ14 standard connectors use a 6P4C, 6 position 4 contact modular connector. They are very commonly used as 2 line telephone cable connector and also as modem connector in computers. The image of a RJ14 standard connector is shown in the following figure.

Image of Male and Female RJ14 connector

Fig. 5: Image of Male and Female RJ14 connector

The pin-out of the 6P4C connector as RJ14

PIN 1 ——————à Absent

PIN 2 ——————à T2

PIN 3 ——————à R1

PIN 4 ——————à T1

PIN 5 ——————à R2

PIN 6 ——————à Absent

RJ 25 Connector

RJ25

The RJ25 standard connectors use a 6P6C, 6 position 6 contact modular connector. They are very commonly used as 3 line telephone cable connector. The image of a RJ25 standard connector is shown in the following figure.

Image of Male and Female RJ25 connector

Fig. 6: Image of Male and Female RJ25 connector

The pin-out of the 6P4C connector as RJ25

PIN 1 ——————à T3

PIN 2 ——————à T2

PIN 3 ——————à R1

PIN 4 ——————à T1

PIN 5 ——————à R2

PIN 6 ——————à R3

RJ 45 Connector

RJ45

The RJ45 standard connectors use 8P8C, 8 position 8 contact modular connector. They are famous for their use as an Ethernet cable connector. This connector can be used with all kind of Ethernet cables including Ethernet (10 Mbps), Fast Ethernet (100 Mbps) and Gigabit Ethernet (1 Gbps). The image of a RJ45 standard connector is shown in the following figure.

Image of Male and Female RJ45 Connnectors