PoE-enabled switch

  Power over Ethernet (PoE) technology allows Ethernet cables to carry both data and electrical power to network devices over a single cable. This eliminates the need for separate power supplies and reduces cable clutter, making the installation of devices like IP cameras, wireless access points, and VoIP phones more efficient. Here’s a breakdown of how PoE technology works:   1. Basic Components of PoE Power Sourcing Equipment (PSE): This is the device that delivers power over the Ethernet cable. It could be a PoE-enabled switch, a PoE injector, or a router with PoE capabilities. The PSE determines how much power is needed and delivers it accordingly. Powered Device (PD): The device that receives both power and data from the Ethernet cable. Examples include IP cameras, wireless access points, VoIP phones, and other networked devices. The PD communicates with the PSE to receive the appropriate amount of power. Ethernet Cable: PoE typically uses standard Cat5e, Cat6, or higher Ethernet cables to transmit both power and data over the same cable. The cable is divided into pairs of wires, some of which are used for data transmission, while others are used for power delivery.     2. How Power is Delivered Over Ethernet PoE technology works by sending low-voltage DC power over the same twisted-pair cables used for data transmission. There are two main methods of delivering power: Spare-Pair Powering (Alternative B): In a standard Ethernet cable, only two of the four twisted pairs of wires are used for data transmission in 10BASE-T and 100BASE-T networks. The unused pairs (pins 4, 5, 7, and 8) can carry power without affecting data transmission. Phantom Powering (Alternative A): In 1000BASE-T (Gigabit Ethernet) and faster networks, all four wire pairs are used for data. In this method, the PSE superimposes the power on the data pairs (pins 1, 2, 3, and 6) without affecting the data signal. This is done by using the DC component of the signal for power delivery while the AC component handles data.     3. PoE Negotiation and Power Allocation The PSE and PD must communicate to ensure that the correct amount of power is delivered. This process is governed by the IEEE PoE standards: Detection: The PSE checks whether the connected device is PoE-compatible by applying a low voltage to the cable. If the PD has a signature resistance of about 25 kΩ, the PSE detects that it is PoE-capable. Classification: The PSE classifies the PD to determine its power requirements. PoE devices are divided into different power classes based on the amount of power they need, ranging from Class 0 (default) to Class 4 (high power). This allows the PSE to allocate the appropriate amount of power and optimize power distribution across multiple devices. Power Delivery: After classification, the PSE begins supplying power to the PD. The voltage is typically between 44 and 57 V DC, with the current varying based on the device's power needs. Monitoring: The PSE continues to monitor the power usage of the PD. If the device is disconnected, the PSE immediately stops providing power to avoid overloading the circuit.     4. PoE Standards PoE technology is standardized under the IEEE 802.3 family of protocols, with different versions specifying varying power levels: --- IEEE 802.3af (PoE): The original PoE standard provides up to 15.4 watts of power at the PSE and up to 12.95 watts at the PD, after accounting for power loss in the cable. This is suitable for low-power devices like VoIP phones and simple wireless access points. --- IEEE 802.3at (PoE+): An enhanced version of PoE that provides up to 30 watts at the PSE and up to 25.5 watts at the PD. This is used for more power-hungry devices, such as IP cameras and high-performance wireless access points. --- IEEE 802.3bt (PoE++ or 4-Pair PoE): The latest PoE standard, which supports higher power levels, offering up to 60 watts (Type 3) or 100 watts (Type 4) at the PSE. This is used for power-intensive devices such as PTZ (pan-tilt-zoom) cameras, LED lighting, and high-performance wireless devices.     5. PoE Advantages Simplified Installation: PoE allows devices to receive both power and data over a single cable, reducing the need for additional power outlets and streamlining installation. Cost Savings: By using PoE, businesses can save on installation costs, avoid the expense of running separate electrical wiring, and reduce the need for power adapters. Flexibility: PoE enables the deployment of devices in locations where power outlets may not be available or convenient, such as ceilings, walls, or outdoor locations. Centralized Power Management: PoE allows for centralized management of power, enabling network administrators to monitor and control the power supply to connected devices. This can improve energy efficiency and simplify troubleshooting.     6. PoE Limitations Power Budget: The total power available from a PoE switch is limited by its power budget. This means that only a certain number of devices can be powered simultaneously, depending on their power requirements. Cable Length: PoE is limited by the maximum Ethernet cable length, which is typically 100 meters (328 feet). BENCHU GROUP's long-distance transmission technology can transmit up to 250 meters without the relay devices. Beyond this distance, power delivery and data transmission become unreliable without using PoE extenders or repeaters.     Conclusion PoE technology is a powerful and flexible solution for powering network devices without the need for separate power supplies. By delivering power and data over a single Ethernet cable, PoE simplifies installation, reduces costs, and provides centralized power management. It's widely used in modern networking environments for devices like wireless access points, IP cameras, and VoIP phones.    

  A PoE splitter is a device that separates the power and data delivered over a single Ethernet cable, enabling non-PoE devices to receive power and data from a PoE-enabled switch or PoE injector. This allows devices that do not support PoE natively, such as older IP cameras, access points, or small networking equipment, to be integrated into a PoE network without requiring separate power adapters or outlets.   How a PoE Splitter Works In a PoE network, power and data are transmitted together over a single Ethernet cable (Cat5e, Cat6, etc.) from a PoE switch or PoE injector to the powered device. A PoE splitter splits these two signals into separate data and power outputs. Here's a breakdown of its functioning: 1.Input: The PoE splitter connects to the Ethernet cable coming from a PoE-enabled device (such as a PoE switch or injector). This cable carries both power and data signals. 2.Splitting Power and Data: Inside the PoE splitter, the device separates the data signal from the power supply: --- Data: The data signal continues through the Ethernet port to the device. --- Power: The power signal is extracted and sent to the device via a separate DC power output (with voltages such as 5V, 9V, or 12V, depending on the device's requirements). 3.Output: --- The Ethernet cable connects to the data port on the non-PoE device, providing network connectivity. --- The DC power cable from the splitter plugs into the device's power input, supplying the necessary voltage to power the device.     Use Case Example Imagine you have an older IP camera that does not support PoE, but you want to integrate it into a modern PoE-powered security network. Using a PoE splitter, you can deliver both data and power to the camera using a single Ethernet cable from a PoE switch. The splitter will separate the data and power, sending the data to the camera via the Ethernet port and the power through the camera's power input (e.g., 12V DC). Advantages of PoE Splitters 1.Eliminates the Need for Separate Power Cables: A PoE splitter allows you to deliver power and data to non-PoE devices using just one Ethernet cable, reducing the need for additional power outlets and simplifying installations. 2.Cost-Effective: It’s a budget-friendly solution to integrate non-PoE devices into a PoE network without upgrading the devices themselves. 3.Flexible Power Supply: PoE splitters usually offer adjustable output voltages (5V, 9V, 12V, etc.) to match the requirements of various non-PoE devices. 4.Extended Reach: PoE splitters can extend the reach of devices up to 100 meters (328 feet) from the PoE switch, which is the maximum standard for Ethernet cable length.     Limitations of PoE Splitters 1.Dependent on Cable Distance: The standard Ethernet cable limit of 100 meters applies to the data and power transfer, which may require PoE extenders for longer distances. 2.Requires PoE Infrastructure: PoE splitters can only function if the source network uses PoE switches or injectors. 3.Limited Power Supply: A splitter can only provide as much power as the PoE standard allows. For high-power devices, a PoE++ splitter may be necessary to ensure sufficient power output.     Conclusion A PoE splitter is an essential tool for integrating non-PoE devices into a PoE network by separating power and data signals. It simplifies the deployment of legacy equipment without the need for separate power sources, offering a practical, flexible, and cost-effective solution for modern network environments.