Registered jacks, commonly referred to as RJ, are standardized physical network interface structures and wiring methods. They are classified based on their wiring, with types including RJ11, RJ14, RJ21, RJ48, and RJ45. Among these, RJ45 and RJ12 are the most frequently encountered in POS systems.
Despite their similar appearance, RJ45 and RJ12 connectors serve distinct functions and have different designs. RJ45 is a common LAN port for POS systems and Ethernet connections. It enables POS systems to connect to the Internet, local area networks (LANs), and other network devices, facilitating seamless data exchange and communication between the various components of the system. Modern RJ45 connectors feature eight pins and eight wires, which support gigabit Ethernet for high-speed data transmission and robust network connectivity.
The RJ12 connector is an evolution of the RJ11, with the main distinction being that RJ12 uses six internal wires (conductors) compared to RJ11’s four. RJ12 also features six pins. The RJ12 is usually used for telephone lines and serial communications. For POS systems, RJ12 is usually used to connect cash drawers, which can provide more stable signal transmission and higher reliability.
Physically, the RJ45 port is larger and generally includes a more secure locking mechanism to ensure a stable connection and prevent accidental disconnections. In contrast, the RJ12 connector is smaller and has a simpler design.
In summary, although RJ45 and RJ12 connectors may look similar, they fulfill very different roles within a POS system. Using an RJ12 port for network connections or an RJ45 port for a cash drawer will not work properly.
Therefore, when choosing a port, you must make sure to choose the right type.