The PoE technology has become a trend in power supply and network communicating. PoE ( Power over Ethernet) provides the solution to send power and data to remote devices by using a single cable. There are many PoE related products, such as PoE switch, PoE extender, PoE injector and so on. All those PoE products play an important role for power supply and network extension. Here we will focus on PoE injector.
Before choosing the suitable PoE injector, let’s understand what a PoE injector is.
A PoE injector or midspan injector can send the power and data through one Cat 5e/Cat 6 network cable. Electricity will be added to the injector and send over Ethernet. Eventually it reaches the remote ip devices. The PoE injector usually has two RJ45 ports, one port for connecting the convenient switch to receive data, and another port for sending out both power and data to remote ip devices such as PoE IP cameras, access point, etc.
The PoE power system is perfectly safe. That is because of the PD signature detection. PD signature detection can avoid machines burned out. What is PD signature detection? The injector sends low voltage power to detect the front-end device before releasing the power. If the PoE injector confirms the remote device does accept the power over Ethernet, the injector will increase the voltage step by step until the end device is working stably. Therefore, the detection process can protect devices effectively.
There are several types of PoE injectors available in the market. Before you choose the right one to be applied in your network. One trap you should avoid. That is the passive injector.
People seldom pay attention to the difference between active injector and passive injector. Active injector complies with the IEEE802.3 standard which is the safe PoE. This kind of injector has PD signature detection as we mentioned above so it will detect whether the signal returned from a remote ip device is correct or not. If a signal is verified, the active PoE injector will increase the voltage gradually to make the device work. Passive PoE injector has removed the function of signature detection, so it can’t detect the feedback signal. Once the Ethernet cable is plugged in, the injector will send the power directly to devices. And this may cause electrical damage to the device. Watch the video to see the difference between passive PoE and active PoE.
Here are several types of injectors you can pick. First type is the PoE injector with IEEE 802.3af or 802.3at compatible. IEEE802.3af provides DC power up to 15.4W, while 802.3at up to 25.5W. Both power and data are injected through the PoE injector, then they will be sent to the device over one Ethernet cable. The PoE injector belongs to active PoE injector. It can detect the power voltage automatically to avoid damage to the device.
PoE switch is also a kind of injector. However it is little different from PoE injector. The PoE switch can be considered as an injector built into a network switch. The PoE switch provides both power and data exchange for remote IP devices such as IP cameras or access points. As the PoE switch has many ports like 8/16/24 ports, more IP devices will be able to connect to PoE switches to receive the power and data exchange.
95W PoE injector is the next generation of PoE injector. It not only meets the IEEE 802.3at/af standard but also 802.3bt, the newest standard. 95W power can be injected to Ethernet cable, so it is suitable for network devices demanding high power.
PoE NVR can be classified to PoE injector. NVR, also called network video recorder, controlS the connected cameras and storeS the video footage conveniently. PoE NVR has integrated PoE technology. It doesn’t need extra power supply and data for exchanging. Power and data will be delivered to cameras after they are connected to PoE NVR. It simplifies the surveillance system setup.
The PoE technology proves the value by saving the installation cost, simplifing the network design. Where the cable goes, the power source follows.
