When building a network system, PoE technology is always good to be considered. PoE (Power over Ethernet) makes power supply and data exchange via one Ethernet cable possible. PoE injector and splitter are two major equipments for transporting the power and data over single ethernet cable. The injector adds the electricity power to Ethernet cable, and the splitter separates the power from the data at the other end. Injector usually has two RJ45 ports, one for receiving data from switch and another for sending out power/data combined signal to the remote devices. Similar as injector, the splitter also has two RJ45 ports. Instead of sending out power and data, the splitter receives data and power and then separates them for non-PoE device.
PoE injector and PoE splitter usually work in pairs. The injector sends out power and data to splitter, and PoE splitter separates data and power into two different cables to make devices work. The PoE injector and splitter solution is designed for non-PoE devices or a mixture of PoE compatible and non-PoE compatible devices.
Except for PoE injector and splitter, a non-PoE switch is required in a typical network system. A non-PoE switch provides platform for connected devices to exchange data. As the PoE injector doesn’t process the data, it has to be connected to a non-PoE switch for data exchange. The PoE injector usually has AC input so it should be plugged in AC power outlet. Now the injector can take the power from outlet and combine it with the data from non-PoE switch before sending out. The splitter stays at the other end of the cable closed to powered device (PD) such as IP camera, access point, VoIP. These powered devices receive the power and data separately from a splitter.
There are three IEEE 802.3 standards for PoE technology. As long as PoE injector and splitter comply with IEEE802.3 standard, it guarantees the power transporting with pre-defined power budget in the system safely.
Different standard provides different power budget. IEEE 802.3at, 802.3af and 802.3bt standard are commonly used. IEEE 802.3af supplies 15.4W, which is the lowest among the three standards. 30.8W power can be provided when the injector and splitter are compatible with IEEE 802.3at (also named PoE+). The IEEE 802.3bt standard is the next generation PoE which increases maximum PoE power up to 95W by taking all 4 twisted pairs wires to transporting the power.
Voltage is another factor in the PoE injector/splitter power system. DC12V and 5V are two main types of power voltage being used in the market. A lot of PoE splitter are designed for DC12V power output. If you use low voltage device like IP camera, 12V PoE splitter is the right one.
Both Cat 5e/Cat 6 ethernet cable can be used to setup PoE injector/splitter power system. Cat 5e/Cat 6 consists of four twisted pairs of wires. Two of the twisted pairs are used for data sending in fast network, which is also called data pair. The spare pairs could be employed to transport the power. Pure copper Ethernet cable should be chosen because pure copper can reduce the power loss on the cable. The electricity transporting on conducts will generate energy loss and be converted to heat. If the low quality cable is picked, the power loss will become serious.
Using PoE injector and splitter solution simplifies network system setup. The AC outlet is removed at the front end and the power is sent by the injector from the center. It is cost-effective and money-saving. Attention should be paid when choosing the PoE injector and splitter.