Unlocking the Secrets of PoE Switches — A Complete Guide

Andy Chen

Power over Ethernet (PoE) switches have gained significant popularity as a practical solution for businesses seeking to conveniently deliver power and data through a single connection. In this comprehensive guide, we will delve into the various types of PoE switches, highlight their advantages and applications, and provide insights on selecting the most suitable PoE switch to meet your specific requirements.

What is a PoE Switch?

A PoE switch combines the functionalities of a switch and a power source into a single device. Equipped with multiple Ethernet ports, these switches facilitate seamless connections with various devices such as VoIP phones, wireless access points, and IP cameras. By integrating power delivery capabilities, PoE switches eliminate the need for separate power cables, streamlining installations. These switches prove particularly beneficial in network deployments where power outlets are limited or in scenarios where devices are situated in challenging-to-access locations.

PoE switches leverage the power over Ethernet (PoE) technology, enabling the simultaneous transmission of data and electrical power through Ethernet cables. This innovative technology employs a combination of power sources and power injectors to deliver power to connected devices. Acting as intermediaries between the power source and the devices, power injectors handle the transmission of both data and power, ensuring efficient operation. Also Check- PoE switch

 


Types of PoE Switches

When selecting a PoE switch, it is vital to familiarize yourself with the various types available. There exist two primary categories of PoE network switches:

The Unmanaged PoE Switch

Designed for simplicity and ease of use, the unmanaged PoE switch offers a plug-and-play solution that suits smaller setups. It requires minimal configuration and is user-friendly. However, it lacks extensive customization options, management features, and advanced security capabilities. Consequently, it is best suited for applications with uncomplicated network requirements, such as home networks or small-scale environments comprising fewer than 5-10 computers.

The Managed PoE Switch

Engineered to deliver enhanced control and comprehensive network management, managed PoE switches excel in scenarios that demand advanced functionality. With their robust security features and extensive configuration options, they prove ideal for applications like enterprise networks, data centers, and large-scale surveillance systems. These switches offer features such as VLANs (Virtual Local Area Networks), QoS (Quality of Service), port mirroring, and heightened port security, catering to complex networking requirements.

Advantages of PoE Switches

Given how PoE switches work, the benefits of PoE switches are obvious.

Simplified Installation: PoE network switches are known for their user-friendly installation and configuration. With plug-and-play functionality, these switches eliminate the need for complex wiring or intricate setup procedures. Built-in features like port mirroring, VLANs, and QoS further simplify network management tasks, enhancing overall operational convenience.

Cost Efficiency: PoE switches exhibit remarkable energy efficiency. By intelligently delivering the precise power required for each connected device, they eliminate the need for oversized power supplies. This efficient power allocation not only reduces energy consumption but also contributes to long-term cost savings, making PoE switches a financially advantageous choice.

Enhanced Flexibility: The ability to power devices through PoE enables easy relocation to areas without available power outlets. This flexibility allows PoE switches to be conveniently placed in challenging-to-reach locations or areas distant from power sources. Security cameras, for instance, can be strategically installed in optimal positions, regardless of the availability of nearby power outlets.

Future-Proofing: With the rapid growth of the Internet of Things (IoT) industry, PoE switches provide future-ready infrastructure. By incorporating PoE switches into your network, you can seamlessly accommodate the increasing number of devices designed to leverage this technology. This scalability ensures long-term compatibility and positions your network for seamless integration with emerging IoT devices.

 

PoE Switch Applications

This rapid expansion of network-connected devices means that PoE technology and PoE switches will grow in importance to most networking infrastructures. While PoE switches have numerous applications, we mainly discuss the three most common application scenarios.

  • VoIP Phones: VoIP phones are PoE devices, with PoE allowing for a single connection to the wall socket and the ability for remote powering down

  • IP Cameras: Security cameras can be connected to PoE switches to enable fast deployment and simple repositioning.

  • Wireless: Many wireless access points are PoE compatible. Thus, PoE switches allow for easy relocation and remote positioning.

  • Smart Home Automation: LED lighting, heating and cooling systems, appliances, voice assistants, and electric car charging stations.

How to Select the Right PoE Switch

When selecting a PoE switch, it is important to consider your application requirements, the features and limitations of the PoE network switch. Of course, the power requirements of connected devices are also important. Some PoE network switches are designed to power devices that require up to 30 watts, and some are even designed for power devices that require up to 60 watts.

Features of PoE Switches to Consider

In addition to the type of switch and power requirements, there are a number of features to consider when selecting a PoE switch. These features include port speed, port count, port types, PoE budget, power savings, and port security.

  • Port speed: Maximum speed a port can achieve. It is important to choose a switch with a port speed that can support the connected devices. The port count is the number of ports available on the switch. It is important to choose a switch with enough ports to accommodate all of the connected devices.

  • Port type: Common port types include RJ45, SFP, and SFP+. It is important to choose a switch with the right port type for connected devices.

  • PoE budget: Maximum amount of power that can be allocated to connected devices. It is important to choose a switch with a PoE budget that can accommodate all of the connected devices.

  • Power savings: Designed to conserve energy by automatically turning off unused ports. This can help to reduce energy costs. 

  • Port security: Designed to protect connected devices from unauthorized access.

Limitations of PoE Switches

Nonetheless, there are some limitations to PoE variation that you should be aware of:

  • Restrictions on distance: Typically, PoE switches can transmit over Ethernet up to a distance of up to 100 meters. The 100-meter distance restriction presents a challenge for large campuses, restaurants, and businesses implementing PoE. However, there are still devices like power extenders and powered fiber cables that can be used to extend the PoE range.

  • Power: If you require high power over poe networks, you must ensure that the power capacity of your PoE switches meets your requirements due to the power limitation imposed by PoE standards and Wattage.

 

FAQs about PoE Switch

Q: Non-PoE vs. PoE Switch: How do they differ?

A: Non-PoE switches cannot deliver power to connected devices, necessitating the use of midspan power sourcing equipment (PSE), such as a PoE injector. This setup adds power while transmitting data to powered devices (PDs). In contrast, PoE switches offer a simpler solution, directly delivering power and data to PDs with just a network cable and a power cable.

Also Check- PoE vs PoE+ vs PoE++ Switch: How to Choose?

 

Q: Do PoE Switches Require Special Cables?

A: No. The Ethernet cables that should be used for PoE network switches primarily depend on the data rate of the PoE port; for instance, Cat3 or better cables can be used for 10/100M; Cat5/Cat5e/Cat6 cables are required for 1000M. In the future, Cat6a or higher cables may be required for the installation of 2.5G/5G/10G PoE devices.

 

Q: Active vs Passive PoE Switch: Should I Choose Active or Passive PoE Switches?

A: Active PoE network switch complies with standard PoE. On the contrary, passive PoE network switch does not adhere to any IEEE standard. There are many ways that active and passive PoE switches differ from one another, like how the PoE power supply pinout looks and whether or not they support Ethernet.

 Also Check- Active vs. Passive PoE Switch: Which Should We Choose?

 

Q: Can the PoE Switch be used with a computer or other non-PoE devices? And will a PoE switch harm devices that do not use PoE?

A: Yes, a PoE switch can be used with non-PoE devices like computers. The switch automatically detects whether a connected device is PoE-compatible and will only supply power to PoE-enabled devices. So, it won't harm non-PoE devices; they just won't receive power through the switch.

 

Q: Is it possible to connect two PoE switches?

A: You could, yes. The PSE only supplies PD with power when it determines that the device can handle it. As PSEs, the two PoE switches will only be used for data communications.

 

Q: What is the maximum transmission distance of PoE? How to extend the transmission distance of PoE?

A: Whether using IEEE 802.3af (PoE) or 802.3at (PoE+), data and power transmission are limited to a distance of 100 meters over Ethernet cables in standard PoE. Media converters and PoE extenders, for example, can extend the range to up to 300 meters if you want to increase the maximum distance.

Conclusion

PoE switches are an effective solution for businesses looking to provide power and data over a single connection. They can simplify installation, reduce clutter, and improve energy efficiency. When selecting a PoE network switch, it is important to consider your application requirements, the power requirements of the connected devices, and the features of the switch. It is also important to consider the cost and long-term cost savings of using a PoE network switch.

If you are looking for a reliable and cost-effective PoE switch, check out Linovision PoE Switches.

Read more →

What Is Power over Ethernet and How to Add PoE to Your Network?

Andy Chen

With the wide application of VoIP phones, IP cameras, and wireless access points, Power over Ethernet (PoE) has made great strides in recent years. And PoE network is expected to expand rapidly in the future due to the increasing number of IoT applications and smart device deployments and newly ratified standards designed to support more smart devices. In this article, we will provide an introduction covering various aspects of PoE such as PoE wiki, PoE standards, PoE types, PoE classes, and PoE applications.

What Is Power over Ethernet (PoE)?

PoE is a networking technology that can transmit both data and power over one single standard Ethernet cable. It allows us to use network cables such as Cat5/Cat5e/Cat6/Cat6a cables to provide data connections and electric power to wireless access points, IP cameras, VoIP phones, PoE lighting and other powered devices (PDs). With the use of PoE technology, we can easily deliver power to indoor or outdoor PDs without the need to install additional electrical infrastructure or to deploy power outlets at every endpoint.

 

Benefits of PoE Network—Why Use Power over Ethernet?

Besides the above-mentioned benefits, there are several more appealing reasons for adopting PoE in networking.

Time & Cost Saving: By using PoE in the network, we do not need to deploy electrical wiring and outlets for terminal PDs. This will help to save much power cabling cost especially when there are lots of PDs in the network. Furthermore, there is no need to hire a qualified electrician for the PoE network, so you may also save both time and money on electrical installations.

Flexibility: Since Ethernet network cables are easier to deploy than electrical ones, PoE networking allows us to install PDs nearly anywhere rather than near the electrical outlets. This offers a ton of flexibility for setting up and repositioning terminal devices.

Reliability: PoE power comes from a central and universally compatible source rather than a collection of distributed wall adapters. It can be backed up by an uninterruptible power supply (UPS) or controlled to easily disable or reset devices. By doing so, the PDs will run as usual even though Power Sourcing Equipment (PSE) breaks down.

Evolutionary Path of the Power over Ethernet (PoE)

Institute of Electrical and Electronics Engineers (IEEE), Cisco, and the HDBaseT Alliance have released several standards to define PoE. These standards include IEEE 802.3af, IEEE 802.3at, IEEE 802.3bt, Cisco UPOE, and Power over HDBaseT (PoH).

Evolutionary Path of the Power over Ethernet (PoE)

PoE Types

Due to different classification standards, PoE can be divided into different types. Currently, there are 4 PoE types based on IEEE PoE Standard: Type 1(IEEE 802.3af), Type 2(IEEE 802.3at), Type 3(IEEE 802.3bt), and Type 4(IEEE 802.3bt), as shown in the following chart.

PoE Types

PoE vs. PoE+ vs. PoE++ (UPoE )vs. PoH

PoE (IEEE 802.3af), also known as PoE type 1, provides up to 15.4 watts of power per port and is used for devices like IP phones and cameras. PoE+ (IEEE 802.3at), PoE type 2, offers up to 30 watts and powers devices like PTZ cameras. PoE++ or UPoE (IEEE 802.3bt), also referred to as PoE type 3, delivers up to 60 watts and 100 watts, PoE type 4, per port for high-performance devices. Power over HDBaseT (PoH) enables power and data transmission for AV equipment over a single cable. The figure below illustrates the common applications of different PoE types for your reference.

PoE vs. PoE+ vs. PoE++ (UPoE )vs. PoH

PoE Classes

Power over Ethernet (PoE) classes define standardized power levels for different network devices. These classes ensure compatibility between Power Sourcing Equipment (PSE) and Powered Devices (PD).

The classes, ranging from Class 1 to Class 8 as the above chart shows, correspond to specific IEEE standards, indicating the maximum power output of the PSE and the maximum power input of the PD. Let’s delve into more details about each class:

PoE Classes

Class 1 is suitable for low-power devices such as IP phones, voice-over-IP (VoIP) devices, and basic sensors.

Class 2 is intended for devices that require slightly higher power, including wireless access points, small IP cameras, and IP intercom systems.

Class 3 is commonly used for devices that require moderate power, such as larger IP cameras, point-of-sale systems, and access control devices.

Class 4 provides increased power delivery capabilities and is suitable for power-hungry devices like pan-tilt-zoom (PTZ) cameras, video phones, and thin clients.

Class 5 introduces the support for four pairs of Ethernet wires, enabling higher power transmission. It is designed for devices with more demanding power requirements, including advanced PTZ cameras, multi-channel wireless access points, and small LED lighting systems.

Class 6 provides increased power delivery capabilities beyond the previous classes. It can support devices like high-power pan-tilt-zoom cameras, multi-radio wireless access points, and small LCD displays.

Class 7 offers even higher power capabilities introduced with the IEEE 802.3bt standard. It is suitable for devices like high-performance access points, large displays, and thin clients requiring substantial power.

Class 8 represents the highest power class defined by current PoE standards. It is designed for power-hungry devices such as video conferencing systems, advanced lighting systems, and digital signage

It’s important to note that the power levels specified for each class represent the maximum allowable values, and the actual power delivered or consumed by the PD may vary based on its specific power requirements and negotiation with the PSE. Besides, understanding PoE classes allows network administrators to ensure that the power requirements of their devices align with the capabilities of their PoE infrastructure, ensuring proper operation and avoiding potential power supply issues.

Passive PoE vs. Active PoE

Power over Ethernet can also be divided into passive PoE and active PoE in general. Active PoE is the standard PoE which refers to any type of PoE that negotiates the proper voltage between the PSE and the PD device. Passive PoE is a non-standard PoE technology. It can also deliver power over the Ethernet line but without the negotiation process.

How to Add PoE to Your Network?

The PoE supplied in the network generally comes from three different sources: PoE switch, PoE injector, and PoE splitter. The PoE switch is the easiest way to power up the PDs. You only need to run Ethernet cables from a PoE network switch port to the terminal PoE device. A PoE injector is used when there is no PoE switch in the network. It has an external power supply and is responsible to add power to data that is coming from a network switch that is not PoE-capable. PoE splitters also supply power, but they do so by splitting the power from the data and feeding it to a separate input that a non-PoE-compliant device can use. It is commonly used for deploying remote non-PoE devices with no nearby AC outlets in the network.

 

Common FAQs on PoE Network

Q: What is the voltage of Power over Ethernet?

A: Power over Ethernet is injected onto the Ethernet cable at a voltage between 44v and 57v DC, and typically 48v is used. This relatively high voltage allows efficient power transfer along the cable, while still being low enough to be regarded as safe.

Q: What data speed does PoE offer?

A: Generally, PoE can deliver data rates at 10/100/1000Mbps over Cat5, Cat5e and Cat6 cables. Now thanks to the widespread IEEE 802.3bt PoE standard and PoE++ technology, PoE is able to deliver speeds of 2.5 Gbps to 5 Gbps over 100m and reaches 10 Gbps in recent times.

Q: Are there any limitations of PoE network?

A: Yes, PoE network does have some pesky limitations. First, it has a restricted reach of 328 feet (100 meters) which limits the viable locations where users can operate a remote IP-enabled device. Second, a single PSE such as a PoE switch usually connects to multiple PDs. If the PSE broke down, all the PDs will stop working. Therefore, it is important to buy qualified switches from a reliable supplier. In addition, you may also consider connecting the PSE to an uninterruptible power supply system.

Q: What are PoE midspan and PoE endspan?

A: The PoE midspan is usually a PoE injector that serves as an intermediary device between a non-PoE switch and the terminal PoE-capable powered device. A PoE endspan, which is commonly called the PoE network switch, directly connects and supplies both PoE power and data to a PD. PoE endspan provides power over the data pairs, also known as PoE Mode A. PoE midspan provides power using the pins 4-5 and 7-8, also known as PoE Mode B.

Read more →

PoE Switch vs PoE Injector: Why Choose PoE Switch to Build Wireless Networks?

Andy Chen

Power over Ethernet (PoE) technology has transformed the way we construct wireless networks by enabling the simultaneous transmission of data and power over a single Ethernet cable. This innovative approach eliminates the need for additional modifications to the existing Ethernet infrastructure, allowing power devices (PDs) like IP cameras and wireless access points to receive power seamlessly. To gain a comprehensive understanding of PoE networks, you can consult resources such as the Demystifying PoE Network: Features, Standards, Types, and Common FAQs guide. When implementing PoE technology, you have two primary options: PoE switches and PoE injectors. In this article, we will delve into the distinctions between these two alternatives and elucidate why a PoE switch is often the superior choice for constructing wireless networks.

What Is A PoE Switch?

A PoE switch is an Ethernet switch equipped with integrated PoE capabilities, enabling it to deliver power directly to connected devices through the Ethernet cable. This eliminates the need for additional equipment, as you can directly connect PoE-enabled devices like IP cameras and wireless access points to the PoE switch using Ethernet cables. The switch seamlessly provides power to the devices, simplifying the setup process and reducing the complexity of the network infrastructure.

 

What is A PoE Injector?

A PoE injector is a device designed to enable PoE functionality in non-PoE network switches or routers. It acts as an intermediary between the non-PoE switch and the PoE-enabled device. By connecting the injector between these two components, it injects power into the Ethernet cable, delivering power to the device. However, it's important to note that utilizing a PoE injector adds an extra step to the installation process. You need to connect the injector to both the PoE-enabled device and the non-PoE switch, ensuring that power is properly supplied to the device.

Build Wireless Networks: PoE Switch vs PoE Injector

While both PoE switches and PoE injectors have the capability to deliver power over Ethernet cables, there are compelling reasons why a PoE switch is frequently considered the superior option when it comes to constructing wireless networks.

PoE Switches Are More Convenient and Easier to Install

PoE switches offer greater convenience and simplicity compared to PoE injectors when it comes to installation. Unlike PoE injectors, PoE switches eliminate the need for additional equipment, streamlining the installation process and reducing cable clutter. With a PoE switch, powering your devices becomes effortless since the switch itself provides power, eliminating the need for a separate injector. On the other hand, utilizing a PoE injector necessitates an additional installation step, potentially consuming more time and requiring extra equipment.

PoE Switches Are More Cost-Effective

When taking a long-term perspective into account, PoE switches provide superior cost-effectiveness. Although the initial investment in a PoE switch may be higher compared to a PoE injector, the overall cost savings over time are significant. By eliminating the need for additional injectors, you avoid the expense of purchasing and maintaining multiple devices. Moreover, the streamlined installation process and centralized power management offered by PoE switches result in time and effort savings, further contributing to cost efficiency.

PoE Switches Offer Greater Flexibility and Scalability

PoE switches provide enhanced flexibility and scalability compared to PoE injectors. With a PoE switch, you have the capability to connect multiple PoE-enabled devices to a single switch, offering the flexibility to expand your network as required. This allows for efficient network management and reduces the need for additional infrastructure. In contrast, a PoE injector can only provide power to a single device, limiting the scalability of your network and potentially requiring the installation of multiple injectors for additional devices. The ability of PoE switches to accommodate multiple devices makes them a more versatile solution for network expansion.

PoE Switches Are More Efficient for Building Wireless Networks

Deploying a wireless network using PoE switches is a more efficient approach compared to PoE injectors. When constructing an enterprise PoE wireless network, the Power over Ethernet switch serves as a connection point between the router and the Internet. This network configuration establishes seamless network connectivity between PoE wireless network devices and computers that are wired to the switch. The PoE wireless access points are directly connected to the PoE switch, receiving both power and network connectivity. These access points facilitate the connection of multiple wireless devices to the network, effectively extending its coverage and capabilities.

The picture below shows a wireless network in an office. The wireless AP is installed on the ceiling. Cat5e or Cat6 network cable delivers data and power from the nearest PoE switch. Compared with the PoE injector, using a PoE Ethernet switch to power the AP is more efficient for the wireless network because you don't need to worry about the power outlets. In addition, you don't have to specifically buy a Cat5e or Cat6 Ethernet cable for power transmission.

Wireless Network in an Office

PoE Switches Offer Better Management and Control Features

PoE switches provide superior management and control capabilities compared to PoE injectors. They come in a wide range of options, catering to various applications, from simple unmanaged edge switches with a few ports to advanced rack-mounted units with extensive management features. With a PoE switch, you gain the ability to easily monitor and control the power usage of connected devices. This allows you to optimize the performance of your network and reduce energy costs by efficiently managing power allocation.

In contrast, PoE injectors lack these management and control features. They simply deliver power to PoE devices without offering the same level of monitoring and control functionality. Furthermore, PoE switches adhering to the IEEE 802.3af standard provide Gigabit speeds, ensuring both power and data transmission over a single cable. This eliminates the need for additional wiring, power sources, or adapters, streamlining the network setup process.

Endspan PoE Switch

How to Choose a PoE Switch for a Wireless Network?

When planning to choose a PoE switch, we recommend that you should take the following three aspects into consideration.

  • The number of ports of PoE switch, which can affect the number of powered devices that can be connected to a PoE switch.

  • The power budget and PoE Standard of a PoE switch are two important points that cannot be ignored, both have an impact on PoE switch's power consumption.

  • In terms of managed or unmanaged PoE switch, one thing is that when connecting with PoE devices like IP cameras, smart managed PoE switches can detect whether they are PoE-compatible and supply power automatically for the remote-powered devices.

For more detailed information about how to choose a PoE switch, you can click: PoE vs PoE+ vs PoE++ Switch: How to Choose? 

Conclusion

In conclusion, while both PoE switches and PoE injectors can provide power over Ethernet cables, a PoE switch is often the better choice for building wireless networks. PoE switches are more convenient, easier to install, efficient, offer greater flexibility and scalability, and provide better management and control features than PoE injectors. By choosing a PoE switch, you can build a more efficient and effective wireless network that meets your needs and helps you achieve your goals. PoE switch is available in Linovision, where you can find a wide selection of PoE switches. For detailed information and product availability, please visit our website at www.linovision.com or contact us.

Read more →

Troubleshooting Common PoE Errors and Solutions

Andy Chen

Introduction:


In a PoE power supply system, the essential components are the Power Sourcing Equipment (PSE), the Powered Device (PD), and the PoE cables. When issues arise with PoE, it often manifests as the PoE switch failing to provide power, resulting in the powered devices ceasing to function. These failures can stem from various factors, including hardware and software-related issues. This article aims to help you accurately identify the root causes of PoE errors and minimize troubleshooting time. We will discuss three common PoE faults and provide troubleshooting methods for Power over Ethernet.

PoE Error 1: PoE Switch Fails to Provide Power

One of the most frequently encountered PoE errors is when a PoE-powered device (PD) fails to boot up due to issues with PoE components or incorrect configuration commands. Follow the steps below to address this problem:

Step 1: Verify PoE IEEE Standards and Power Modes of PSE and PD

Ensure that both the Power Sourcing Equipment (PSE) and PD comply with PoE IEEE standards. It's important to note that non-standard PoE switches, also known as passive PoE switches, deliver power over Ethernet lines at a fixed voltage, regardless of whether the terminal device supports PoE or not. Improperly prepared passive PoE switches may damage the terminal devices. Additionally, the power modes of PSE and PD can contribute to PoE faults. There are three PoE modes: Alternative A, Alternative B, and 4-pair delivery. If a PD supports only PoE mode B power delivery while the PoE switch is based on Alternative A, they will not work together. Confirm the power supply modes of PSE and PD with the vendor.

Step 2: Check the PoE Cabling

Mismatched Ethernet cables and PoE ports can result in network failures. Furthermore, PoE failures can occur if the cable has hardware faults or fails to meet necessary standards. Therefore, it's highly recommended to ensure that the Ethernet cable supports PoE and is functioning properly before connecting the powered device.

Step 3: Verify Sufficient PoE Power

In theory, the PSE device interface can automatically detect the connected PD. If the power supply is insufficient, the PD will not receive power. Make sure that the power required to run the PDs does not exceed the power budget of the PoE network switch. If a PSE detects that the PD's power class falls within its capacity, it will power on the PD.

Step 4: Check PoE Power Management Configuration

Verify whether the switch interface has automatic PoE power management configuration enabled. If not, you will need to manually deliver PoE power to the connected PDs through the PoE network switch interfaces.

PoE Error 2:  Intermittent Power Loss or Reloads of a PoE PD

What if a functioning PD experiences intermittent power loss or reloads? These situations may arise due to insufficient power supply and poor-quality PoE cables.

Step 1: Check Whether PoE Power Is Sufficient

A PD can power off or reload intermittently if the PSE's output power is insufficient to support all PDs operating at full power consumption. This can cause the PoE switch to fail to provide power. Take IP cameras as an example. During testing of extended functions such as Pan-Tilt-Zoom, heaters, or wipers, the PD may consume significantly more power than during normal operation. If no additional power is available, the camera may get stuck in a continuous boot cycle. To troubleshoot this PoE fault, measure the power requirements of the IP camera during startup and use an appropriate PSE to provide sufficient power.

Step 2: Check the PoE Cabling

If the Ethernet cable used in a PoE link is over 100 meters or has power loss due to the material and resistance of the cable itself, the PD would not get sufficient power, causing issues like network failure or latency. If the cables are not qualified, it will lead to PoE faults as well.

PoE Error 3: Inconsistent Powering of PDs on the Same PSE

If some PDs are receiving power while others connected to the same PSE are not, follow the tips below:

Step 1: Check if PDs Are Available on Other Ports

Determine whether the issue lies with specific ports on the PSE. Disconnect the PoE cable between the Ethernet switch port and the non-powered PDs. If the PDs receive power when connected to other PoE ports, it indicates a problem with specific ports. Verify if the port is shut down or error-disabled using configuration commands. If so, enable PoE functions through the appropriate command.

Step 2: Check the PoE Power

If newly added PDs to PSE ports are not powering on, it may indicate that the PoE switch's power budget is depleted. Ensure that the remaining PoE power in the PSE is equal to or greater than the maximum output required by the connected PDs. Additionally, limit the per-port current to safe levels and consider using additional PSE devices if necessary.

PoE Error 4: PoE Cameras Not Powered

If your camera cannot be powered on while using a PoE Switch or PoE injector, you may follow the tips below to solve your problems.

Step 1: Verify Camera Compatibility with PoE Switch/Injector

Check the compatibility requirements of your camera with the PoE switch or PoE injector. Ensure that the specifications of the PoE switch or injector align with the camera's requirements.

Step 2: Check if the Camera Is Fully Connected to the PoE Switch/PoE Injector

Inspect the PoE port lights on thePoE switch or PoE injector to confirm if the camera is fully connected. If the lights are not illuminated, try plugging the camera into other ports and using a different Ethernet cable. Also, check if the PoE port of the switch is damaged or rusty. You can test this by connecting the camera to other functioning PoE ports.

Step 3: Check if the PoE Module of the Camera Gets Power

If the camera's PoE module is not receiving power, use a DC adapter with the correct output voltage to power the camera. Make sure the DC/AC adapter is available and compatible. Typically, the adapter has an indicator light that indicates the presence of power. Some IP cameras support both DC and AC power supply ports, such as DC12V/2A and AC 24V/3A. Verify that the adapter's specifications match those of the camera.

Conclusion

The four errors mentioned above basically cover the problems that PoE switches are often prone to. If you meet other problems in the process of using PoE switches, you can contact Linovision IT experts for answers. Linovision not only provides you with cost-effective and excellent quality PoE switches but also provides a series of technical support services to ensure your after-sales worry-free.

Read more →

Active vs. Passive PoE Switch: How to Choose?

Andy Chen

PoE switch is designed to offer both network connection and power supply to one PoE powered device (PD) through one Ethernet cable. And as the demand for deploying PD devices such as IP phones, IP cameras and access points increases, PoE switch is commonly used in today's enterprise and campus networks for it helps to reduce deployment complexity and cost. Now we can see there are both active PoE switch and passive PoE switch sold in the market. What exactly are they? Should we use active PoE or passive PoE switches for our network?

What Are Active PoE and Active PoE Switch?

Active PoE, short for active Power over Ethernet, is also known as standard PoE which refers to any type of PoE that negotiates the proper voltage between the power supply equipment (PSE) and the PD device. An active PoE switch is a device that complies with standard PoE, so it is also named a standard PoE switch. This type of switch is rated to be IEEE 802.3af, IEEE 802.3at or IEEE 802.3bt compliant. Thus it can be further divided into PoE, PoE+ and PoE++ switches (PoE vs PoE+ vs PoE++ Switch: How to Choose?). Before powering up, the active PoE switch will test and check to ensure the electrical power is compatible between the switch and the remote device. If it isn’t, the active PoE switch will not deliver power, preventing any potential damage to the non-PoE device.

 

What Are Passive PoE and Passive PoE Switch?

Passive PoE, also known as the passive Power over Ethernet, is a non-standard PoE. It can also deliver power over the Ethernet lines, but without the negotiation or communication process. The passive PoE switch does not adhere to any IEEE standard. The power is "always-on" when using a passive PoE switch in networks, which means it always sends electric current out over the Ethernet cable at a certain voltage regardless of whether the terminal device supports PoE or not. So using passive PoE switch may burn out the terminal devices if they're not prepared for electrified Ethernet cables.

 

Active vs. Passive PoE Switch: What Are Their Differences?

As mentioned above, active PoE switches and passive PoE switches can both provide PoE connections but in very different ways. Besides that, they also differ in PoE power supply pinout, Ethernet support, cost, etc.

Active vs. Passive PoE Switch: PoE Power Supply Pinout

As we know, there are three methods for PoE switches to supply power: PoE Mode A, PoE Mode B and 4-pair PoE. In PoE Mode A, power is delivered simultaneously with data over pins 1, 2, 3, and 6. In PoE Mode B, power is injected onto pins 4, 5, 7, and 8. And 4-pair PoE delivers power over all 8 pins simultaneously. Active PoE switch can support all PoE Mode A, PoE Mode B and 4-pair PoE, while passive PoE switch can only support PoE Mode B. 

 

10/100BASE-T Network 1000BASE-T Network
Pins at Switch PoE Mode A (Data & Mixed DC) PoE Mode B (DC on Spares) 4-pair PoE PoE Mode A (Bi-Data & DC) PoE Mode B (Bi-Data & DC) 4-pair PoE
Pin 1 Rx+ & DC+ Rx+ Rx+ & DC+ TxRx A+ & DC+ TxRx A+ TxRx A+ & DC+
Pin 2 Rx- & DC+ Rx- Rx- & DC+ TxRx A- & DC+ TxRx A+ TxRx A+ & DC+
Pin 3 Tx+ & DC- Tx+ Tx+ & DC- TxRx B+ & DC- TxRx B+ TxRx B+ & DC-
Pin 4 Unused DC+ DC+ TxRx C+ TxRx C+ & DC+ TxRx C+ & DC+
Pin 5 Unused DC+ DC+ TxRx C- TxRx C- & DC+ TxRx C- & DC+
Pin 6 Tx- & DC- Tx- Tx- & DC- TxRx B- & DC- TxRx B- TxRx B- & DC-
Pin 7 Unused DC- DC- TxRx D+ TxRx D+ & DC- TxRx D+ & DC-
Pin 8 Unused DC- DC- TxRx D- TxRx D- & DC- TxRx D- & DC-

Active vs. Passive PoE Switch: Ethernet Support

Active PoE switches can support 10/100/1000Mbps Ethernet up to 100m over Cat5/5e/6 cable. Passive PoE switches, however, commonly support 10/100 Mbps Ethernet up to 100m. Thus active PoE switches can be applied in both traditional 10/100BASE-T and modern 1000BASE-T PoE networks. While passive PoE switches are usually used in the past 10BASE-T and 100BASE-T PoE networks.

Active vs. Passive PoE Switch: Cost

All active PoE switches are equipped with the built-in PoE power controller which performs the function of PD device detection and classification. While the passive PoE switch has no such component and function. Therefore it is reasonable to see the price of the active PoE switch is higher than that of the passive PoE switch.

To sum up, active and passive PoE switches mainly differ from each other in the following aspects:

 

Active PoE Switch Passive PoE Switch
Standard IEEE 802.3af/at/bt N/A
Power Injection After Negotiation Immediately
Power Supply Mode PoE Mode A/PoE Mode B/4-Pair PoE PoE Mode B
Ethernet Support 10/100/1000BASE-T 10/100BASE-T
Max. Distance 100m 100m
Safety High Low
Cost Medium Low

 

Active vs. Passive PoE Switch: Which to Choose?

From the above content, we can say that for safety concerns, active PoE switches should always be our top choice for powering up remote IP phones, IP cameras, wireless access points, and other PD devices. However, you may also consider passive PoE switches if there is a tight budget. But remember that the passive PoE switch has no power detection function. So it is important to make sure the passive PoE switch you buy matches the power specifications exactly to the PD device you are trying to power on. Otherwise, you can easily burn up your PD device. In addition, you should never connect computers and other non-PoE devices to the passive PoE switch.

Read more →