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PoE Power Solution-PSE: PoE Switch VS. PoE Injector

PoE technology has successfully made its way into every corner of our lives. It’s a widely acceptable power solution to provide uninterruptible power to IoT products (i.e. IP cameras, wireless access points and VoIP phones). In the scenario of PoE, devices are divided into PSE and PD. Up to now, the most well-known power supply devices are PoE switch, PoE injector, PoE NVR and PoE media converter. In this blog, we’re gonna figure out the differences between the PoE switch and PoE injector and their applications as well.

A complete PoE system: PSE+PD

The PoE system is basically composed of two parts: power sourcing equipment (PSE) and powered devices (PDs). PSE refers to devices that deliver power to the connected devices on different PoE standards (IEEE 802.3af/at/bt) to facilitate PoE installation and management in different scenarios, from residential/commercial to industrial applications. The most common PSEs are network switches (endspans) and PoE injectors (midspans), intermediary devices that supply power to PoE and non-PoE devices. PDs are devices that receive power from the PSE, and additionally, most PDs have an auxiliary connector for external power supplies.

What is a PoE switch?

The PoE switch is a network switch with a built-in injector, which serves as a vital point to transfer electrical energy as well as digital signals to the terminal devices through the same cable on a twisted-pair cabling system at a maximum distance of 100 meters, eliminating the need for additional power cabling or electrical infrastructures. A reliable power source is guaranteed from a centralized source rather than multiple randomly distributed wall outlets. PoE switches can be roughly divided into managed or unmanaged switches according to their manageability and configurability. And based on the port numbers, the PoE switches can be classified into 4/8/16/32/64-port PoE switches along with corresponding LED indicators to showcase the power consumption of each port. Nearly every PoE switch will have at least 2 uplink ports for network connection and data uploading (router and NVR).

As a crucial part of the entire network system, the active PoE switch has auto-sensing PoE ports that will automatically detect whether the connected devices are PoE-compatible or not (the passive PoE switch doesn’t support IEEE 802.3 standards). This PoE detection, namely the handshake procedure, helps it lowers the chances of power outrages and operation failures and prevent irreversible electrical damages to the PDs caused by overload or underload. It is inherently safe owing to its improved reliability with uninterruptible and redundant power supplies to guarantee the ongoing functionality of the PDs. It is hot-swappable featuring a user-friendly installation (plug and play; no licensed electricians involved). It offers great flexibility for installation and relocation without the necessity of being hardwired to electrical outlets, which helps to improve the scalability of network architecture and reduce the costs of the initial investment.

What is a PoE injector?

The PoE injector plays more of a supporting or supplementary role in the entire PoE system to enable the regular network switch to work with the PoE-compatible devices and support high-power devices in long-distance deployments. A PoE injector normally has three ports: a power input port, a data input port and a power/data output port. It offers a versatile solution to power the PDby converting the AC power drawn from the electrical outlet into DC power, integrating the power and data into one source and transmitting it to the PD. It usually works together with PoE or non-PoE switches for networking and data uploading. Furthermore, it can also work with a PoE splitter to deliver power to the non-PoE devices.

The PoE injector quickly makes its way into the existing networks with decreased electrical hazards and reduced installation costs. It creates connections to high-power applications, such as 90W smart LED lighting, PTZ cameras and high-performance wireless access points, with improved network speed and less latency. Compared with the PoE switch, it leaves a smaller footprint taking less equipment for PoE deployments, which makes it ideal for applications where only 1-2 PoE ports are demanded. As a matter of fact, it’s a miniature of an unmanaged PoE switch but with fewer ports. To learn more about the PoE injector, please continue to read Comprehensive Knowledge Base of PoE Injector. Both PoE switches and PoE injectors can be active or passive, varying in the amount of voltage they could provide. According to the IEEE 802.3 standards, they can also be classified into PoE, POE+ and POE++.

Differences between a PoE switch and a PoE injector

1. The primary difference would be their constructions and designs. A PoE injector has only one PoE port and it can only power one device at a time, while a PoE switch has at least 4 PoE ports (4/8/16/32/64) with 2 uplink ports depending on the manufactures and it can power multiple PoE-enabled devices at a time. But since the PoE switch has more ports, the power distributed to each port is quite limited as compared with the PoE injector, which gathers all possible energy in one port. Moreover, the former usually works with a non-PoE network switch to inject the PoE capability into the end unit, while the latter can function on its own when connected to the Internet. The PoE injector features a compact and light-weight design which is easy for wall-mounting, while the PoE switch is way bulkier and heavier.

2.The PoE injector is less expensive than the PoE switch on a per-unit basis for its limited functionality. With this powerful PoE device, you can save a large amount of money on replacing non-PoE network switches and installing new electrical outlets. The PoE switch seems to be more cost-effective when more PoE ports are required especially in long-term applications. More cables are needed to set up a PoE injector (every injector needs a power cord and two Ethernet cables for installation), which will lead to a jumble of messy cables if not well-maintained and force you to install more AC outlets to power the injectors. The PoE switch only needs one power cord to set up multiple terminal devices, and every connection can be completed by a single Ethernet cable for both power and data transmission.

3. Another distinct difference between the PoE switch and injector lies in their manageability and scalability. As previously mentioned, the injector is the miniature of an unmanaged PoE switch, featuring simple plug-and-play without complicated software configuration, while the PoE switch can be sub-categorized into the managed and unmanaged switch. The managed PoE switch offers full management capacities with high levels of network security, control, and management. It allows authorized administrators to regulate the voltage coming out of each port and monitor the activity of incoming traffic with a wide range of troubleshooting. Besides, the PoE injector normally leaves no room for future expansion, while the PoE switch offers endless scalability and expandability for escalating the networks.

Deploying the right device for your network

If you have a functioning network switch without PoE, using the PoE injector is the simplest method to expand the network capacity without a large-scale change of the existing network switches. And it’s also recommended in situations where only a few terminal devices need to be powered or in circumstances when you want to connect a remote device far away from the PoE switch without running long rolls of cables. The injector provides a practical solution to set up the power connection between non-PoE and PoE devices and to deliver higher levels of performance to start up high-power devices. Its point-to-point connection can efficiently lower the chances of power failures. For networks that deploy a large number of PoE-enabled devices, the PoE switch is obviously a more economical choice to set up a large and complicated network system with centralized management and monitoring. A managed PoE switch is needed especially when you want to run some mission-critical devices like security cameras to monitor and prioritize the traffic.

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