These connectors look similar, but they have different uses, pin counts, and functions. Let's take a look at the specific differences:
1. RJ9
Purpose: Mainly used to connect telephone headsets, like the ones you have in your office.
Number of pins: 4.
Appearance: Small, suitable for low-bandwidth devices.
Configuration: Usually only 2 or 3 pins are used.
2. RJ11
Purpose: This is a common telephone connection cable in our homes.
Number of pins: Usually 6, but not all are used.
Appearance: Slightly larger than RJ9, more common.
Configuration: The most commonly used is 2 pins, and there is also a 4-pin version for fax and other telephone services.
3. RJ12
Purpose: For multi-line phones or some data devices.
Number of pins: 6.
Appearance: Looks similar to RJ11, but can connect more lines.
Configuration: Uses 6 pins, suitable for multi-line phone systems or devices with more functions.
4. RJ45
Purpose: This is a common connector for network devices such as computers, routers, switches, etc. in our homes or offices.
Number of pins: 8.
Appearance: It is relatively large and is specifically used to connect network devices.
Configuration: It uses 8 pins to transmit data. There are two common wiring methods, called TIA/EIA 568A and TIA/EIA 568B.
5. RJ48
Purpose: It is used for more professional communication equipment, such as lines that transmit high-bandwidth signals.
Number of pins: 8 (same as RJ45).
Appearance: It looks similar to RJ45, but is specifically used for communication lines with higher requirements.
Configuration: It is not the same as RJ45. It has its own specific pin arrangement for transmitting high-bandwidth digital telephone signals.
Summary
RJ9: For telephone headsets, 4 pins.
RJ11: For ordinary phones, usually 6 pins, but not all are used.
RJ12: For multi-line phones, 6 pins.
RJ45: For network connection, 8 pins.
RJ48: For high bandwidth communication, 8 pins, very similar to RJ45.
