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.

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).

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 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 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:

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.

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.

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.

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.

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

To enhance comprehension of the PoE network system, it is essential to become acquainted with the PoE devices, as the initially published IEEE802.3af standard categorized Power over Ethernet (PoE) technology into two primary types of power devices: power sourcing equipment (PSE), which supplies power over the Ethernet cable, and powered devices (PD), which receive the power. Presented below is an introduction to power sourcing equipment and a selection of frequently asked questions.

• PoE PSE (Power Sourcing Equipment): PoE PSE denotes the equipment supplying power to PoE PDs. It can take the form of a PoE switch or a PoE injector. The PoE PSE injects power into the Ethernet cable, alongside data signals, enabling connected PoE PDs to receive both power and data through a single cable. It serves as the power source for PoE devices.

• PoE PD (Powered Device): PoE PD refers to the device that draws power from the PoE network infrastructure. It encompasses various device types, such as IP phones, wireless access points, IP cameras, and network switches. The PoE PD consumes power from the PoE PSE, allowing it to operate without the need for a separate power source. Typically, it features an Ethernet input for data communication and a power input to receive power from the PoE PSE.

IP cameras play a crucial role in business surveillance systems, providing visibility and insights into your operations. They are equally popular for home security purposes. PoE switches for IP cameras have become increasingly common, simplifying cabling by combining power and data transmission over a single Ethernet cable. These switches offer versatile solutions for both home and business surveillance needs. In this article, we will discuss the key factors to consider when choosing a PoE switch, share some purchasing tips, and empower you to make an informed decision that aligns with your specific requirements.

Why Use the PoE Switch for IP Camera Systems?

• Power and Data Integration: The PoE switch efficiently combines power and data transmission on a single line, eliminating the need for separate power supplies for each camera or traditional power boxes.
• Extended Cable Runs: PoE switches enable longer distance connections without concerns about voltage loss or cable quality. While Ethernet is typically limited to 328 feet, the range can be easily extended by using PoE network switches or extenders. This flexibility is particularly beneficial for outdoor and large-scale surveillance setups.
• Simplified Cabling: With PoE technology, both power and data can be transmitted through a single Ethernet cable. This simplifies the cabling process and reduces installation costs.
• Multiple Device Connectivity: PoE switches are available in various port configurations, allowing you to connect multiple IP cameras and other PoE devices to a single switch. This facilitates efficient management and scalability within your surveillance system.

How to Choose The Suitable PoE Switch for IP Camera Systems?

Factors to Consider When Choosing a PoE Switch for IP Security Cameras:

1. Port Speed, Port Numbers, and Power Requirements: Consider the bandwidth capacity offered by the PoE switch, such as fast-Ethernet switches (10-100 Mbps) or gigabit switches (1 Gbps). Evaluate the number of ports needed to connect your IP cameras and ensure their power requirements are supported.
2. Power Supply Voltage: Verify that the switch's power supply voltage matches the voltage requirements of your IP cameras to prevent malfunctions and potential damage.
3. Power Budget: Assess the switch's power budget, which is the maximum wattage it can provide. Make sure the total wattage required by the connected devices, including IP cameras, does not exceed the switch's maximum power budget. Check the budget per port to ensure it can adequately power your cameras.
4. Managed vs. Unmanaged PoE Switches: Determine whether you require a managed or unmanaged PoE switch. Unmanaged switches are plug-and-play, suitable for simple setups and home users. Managed switches offer advanced features like network optimization, remote control, and enhanced network status monitoring, making them ideal for larger surveillance projects in enterprises or large facilities.

Tips for Choosing the Right PoE Switch for Your IP Camera System:

• Calculate Power Requirements: Determine the total power needed by your IP cameras and ensure the PoE switch's power budget can handle the load.
• Plan for Expansion: Consider potential future camera expansions and choose a switch with additional ports to accommodate future growth.
• Consider Environmental Conditions: If your cameras will be installed in harsh environments, opt for industrial PoE switches that are specifically designed to withstand extreme conditions.
• Evaluate the Scale of the Project: For large-scale surveillance projects, a managed PoE network switch provides greater flexibility, control, and oversight, allowing for optimized network performance and centralized management.

By following these tips, you can select a PoE switch that meets your specific power requirements, allows for future scalability, suits the environmental conditions, and provides the desired level of control and management for your IP camera system.To make an informed decision, consider the following tips.

How to Connect IP Cameras to a PoE Switch?

Connecting IP cameras to a PoE switch might sound complex, but it's relatively straightforward. Here are the general steps involved:

1. Start by connecting your router to the LAN port on the PoE switch using an Ethernet cable (Cat5e or Cat6). This establishes the network connection between the switch and your router.

2. Plug the power cable into the PoE switch and connect it to a power outlet or a surge protector. This provides power to the switch and ensures its operation.

3. Take Ethernet cables and connect each IP camera to the available ports on the PoE switch. Ensure a secure and stable connection by properly inserting and securing the cables.

4. To view and record the footage from the IP cameras, add them to your Network Video Recorder (NVR) or a compatible surveillance software. This step allows you to manage and access the camera feeds.

5. If remote access is required for viewing the camera feeds from outside your local network, make sure your router is connected to the internet. This enables remote access to the cameras using the appropriate network configurations.

Note: If you need a PoE switch for demanding environments like traffic control cabinets, factory floors, or outdoor locations with extreme temperatures, consider Linovision's industrial PoE switches. These switches comply with IEEE 802.3af/at PoE standards, automatically detect power requirements, and provide power accordingly. They are designed to withstand high levels of vibration and shock, making them ideal for outdoor surveillance deployments in harsh conditions ranging from -40°C to 75°C.

Summary

Selecting the appropriate PoE switch is crucial to ensure an efficient and dependable IP camera system. By taking into account factors such as port numbers, power supply voltage, power budget, maximum power supply, bandwidth capacity, and the choice between managed and unmanaged switches, you can tailor your selection to meet your specific requirements. At Linovision, we offer a range of PoE switches including unmanaged and managed options with varying port configurations (4-port, 5-port, 8-port, 16-port, 24-port), as well as industrial switches designed for diverse IP camera security systems. For more information, please visit the Linovision PoE Switches page.

Power over Ethernet (PoE) is a well-established technology that allows both data and power to be transmitted over the same Ethernet cable, providing significant time and cost savings for local area networks (LANs). In today's market, you will come across different types of PoE switches, including PoE switches, PoE+ switches, and PoE++ switches. But do you understand the differences between these three types? And how do you make the right choice among them?

What Is PoE and PoE Switch?

What is PoE? Power over Ethernet (PoE) is a technology defined by the IEEE 802.3af standard in 2003. It enables powered devices (PDs) such as VoIP phones to receive power, up to 12.95W, through Ethernet cabling using two of the available twisted pairs.

Then what is a PoE switch? A PoE switch, on the other hand, is a type of power sourcing equipment (PSE) that incorporates PoE technology. It provides power to PDs via Ethernet cables, facilitating network connectivity. Typically, an 802.3af PoE switch supports a maximum power consumption of 15.4W per PoE port, with a voltage range between 44V and 57V. The PDs connected to the PoE switch operate within a voltage range of 37V to 57V.

What Is PoE+ and PoE+ Switch?

PoE+ technology, defined by the IEEE 802.3at standard in 2009, is an advancement of PoE technology. With increasing power requirements of devices like wireless access points, PoE+ was introduced to support higher power consumption.

Similar to PoE switches, PoE+ switches also deliver power over two pairs of Ethernet cables. However, PoE+ adds an additional power class that can provide up to 25.5W of power to a powered device (PD) within a voltage range of 42.5V to 57V. Each port of a PoE+ switch can deliver a maximum power of 30W within a voltage range of 50V to 57V.

What Is PoE++ and PoE++ Switch?

In the pursuit of providing even more power for a wider range of devices, the IEEE 802.3 standard further upgraded PoE+ technology to PoE++ (IEEE 802.3bt standard) in 2018. PoE++ is divided into two types: Type 3 and Type 4. Type 3 enables power delivery of up to 51W to a PD using either two or all four twisted pairs in a copper cable. Type 4 allows power delivery of up to 71W to a PD using all four twisted pairs in an Ethernet cable.

PoE++ switches are the next generation of PoE+ technology. They support up to 60 watts of power per port under Type 3 and provide the highest power level for Power over Ethernet switches, delivering up to 100W per PoE port under Type 4.

PoE vs. PoE+ vs. PoE++ Switch: Which to Choose?

The choice of a PoE switch depends on specific requirements. To help make an optimal selection, consider the following aspects: specifications and applications.

Specifications of PoE vs. PoE+ vs. PoE++ Switch

Based on the information provided, the following reference chart summarizes detailed specifications of PoE, PoE+, and PoE++ switches:

Note: The provided figures are theoretical and the total power capacity of PoE series switches in real-world applications may be oversubscribed when multiple devices use less than the maximum power. For example, having a switch with all PoE++ Type 4 ports doesn't mean all ports will be utilized at maximum load 24/7. Therefore, it is important to calculate the power requirements of all connected powered devices and choose appropriate patch cables for your PoE design.

Applications of PoE vs. PoE+ vs. PoE++ Switch

The key differences between PoE, PoE+, and PoE++ switches lie in their operational modes and power delivery, which determine their applications.

PoE switch

An 802.3af switch, also known as a PoE Type 1 switch, is typically used to support devices that require power delivery of less than 15.4W. Examples include:

• Basic VoIP phones used over the internet

• Wireless access points with two antennas for small networksStationary security cameras without pan, tilt, and zoom

• Sensors, meters, etc.

• Stationary security cameras without pan, tilt, and zoom functionality

PoE+ switch

PoE+ switch with 30W output can power Type 2 devices, such as:

• IP telephones that offer fax, text messaging, and voice calls

• Wireless access points with six antennas

• Remote-controlled pan, tilt, and zoom (PTZ) surveillance cameras

• Biometric sensors that collect biological characteristics

PoE++ switch

A PoE+ switch with 30W output is capable of powering Type 2 devices, such as:

• Two-way video phone calls in a conferencing system

• Building management devices such as gate or door controllers

• Thin clients connected remotely to a server-based computing environment

• Remote patient monitoring devices

And the PoE++ Type 4 switch can support devices such as laptops and TVs.

If your data center or network has relatively low power requirements, a PoE switch would be suitable. However, if you need a more powerful and versatile network that can accommodate a diverse range of devices, a PoE+ or PoE++ switch would be a better choice. These switches offer increased power capacity and performance, allowing for more devices to be connected without being limited by port restrictions. They are particularly beneficial when building infrastructures with higher demands or when planning for future upgrades.

Of course, if your existing PoE network design meets your current demands and is adequate for your requirements, there is no need to change it. It is always wise to assess your specific needs and choose the appropriate switch that aligns with your power and performance requirements.

Linovision PoE++ Switch

The main features of three Linovision PoE++ switches are shown below.

Conclusion

As power requirements continue to increase, the evolution of PoE technology has led to the development of PoE+, and subsequently PoE++. Similarly, PoE-based switches have advanced to PoE+ switches, and now to PoE++ switches. This article has provided insights into the distinctions between PoE, PoE+, and PoE++ switches, as well as their respective applications. We hope this information has inspired you to select a suitable PoE network switch for your needs.

PoE (Power over Ethernet) technology revolutionizes the way power and data are transmitted over Ethernet cables. It enables Power Sourcing Equipment (PSE), such as a PoE switch, to deliver power and data simultaneously to Powered Devices (PD), including IP cameras and VoIP phones. This integration simplifies cabling installation, eliminates the need for separate power cables, and reduces overall costs.

To regulate the power delivery to PDs, the Institute of Electrical and Electronic Engineers (IEEE) has established various PoE standards, including IEEE 802.3af, 802.3at, and 802.3bt. These standards define the maximum power that PSEs can provide and the power requirements for PDs.

Let's delve into the details of these PoE standards and their associated wattage.

PoE Standards Introduction

PoE standards encompass three main types: IEEE 802.3af, IEEE 802.3at, and IEEE 802.3bt. These standards establish the minimum power that Power Sourcing Equipment (PSE) can provide and the maximum power that Powered Devices (PD) can receive.

Understanding PoE Wattage

As previously explained, IEEE 802.3af provides a maximum power output of 15.4W per port, while PoE+ (IEEE 802.3at) supports up to 30W. However, when connecting multiple devices to a single PoE/PoE+ switch, it becomes crucial to ensure that the combined power requirements of these devices do not exceed the maximum power wattage supported by the switch. This ensures that the switch can reliably provide sufficient power to all connected devices without overloading its capacity. Careful consideration and planning are necessary to avoid exceeding the switch's power limitations and maintain stable operation.

For example, let's take the LINOVISION POE-SW708GM-DC12V, a managed PoE++ switch with 8 RJ45 ports and 2 SFP ports. Compliant with IEEE 802.3af/at/bt standards, this switch has a total power budget of 240W. This means it can concurrently power 8 devices compliant with PoE+ standards (30W x 8 = 240). It can also support 8 devices compliant with PoE standards (15W x 8 = 120W).

However, there is no need for concern as modern network switches are designed to be intelligent. When a device is connected, the switch automatically detects whether it is compatible with PoE or PoE+. If the device requires a low power of 5W, the switch supplies exactly that amount. If the device demands a higher power of 20W, the switch adjusts accordingly. And if you connect a device without PoE capability, rest assured that the switch will provide data transmission only.

How Much PoE Wattages are Need?

The power needs of your devices depend on what you're connecting. Most devices, such as security cameras, IP phones and standard wireless APs, require no more than 30 watts.

However, certain devices, such as 802.11ac wireless access points with multiple USB ports and radios, may require over 30 watts for optimal performance. In such cases, PoE++ or PoH switches are the ideal solution. It's worth noting that some devices can adapt to lower power availability by using fewer radios or disabling certain features.

Linovision Managed Switches: Your PoE Solution

At Linovision, we offer a range of PoE/PoE+/PoE++ switches that comply with the PoE standards, providing enhanced security and improved capabilities. These switches are available in 4,5,8 and 48 port options. They support layer 2+ switching features like VLAN and offer advanced management options such as WEB, CLI, TELNET, and SNMP. FS PoE/PoE+ switches can power any 802.3af or 802.3at compliant device on the market, providing flexibility and security. The table below provides specifications for four of our PoE/PoE+/PoE++ switches:

Summary

It is essential to have a clear understanding of PoE standards and wattage to ensure effective device connections. By aligning your devices' power requirements with the appropriate PoE standard, you can ensure smooth and reliable operation. PoE technology simplifies complex cabling setups and offers flexibility in power delivery.

Driven by the need for connectivity and monitoring of smart IoT devices, the PoE switch has evolved into an increasingly efficient method of delivering power and data over the network. This article aims to explain the operational principles and modes of the PoE switch's power supply, as well as the limited distance and maximum voltages associated with PoE switch supply.

Devices in PoE Network

A PoE network consists of two types of devices: power sourcing equipment (PSE) and powered devices (PD). The PSE supplies power to the PD. The PSE device typically takes the form of a PoE switch, while the PD devices encompass IP phones, IP surveillance cameras, wireless LAN access points, PoE lighting, and similar devices.

Working Process of PoE Switch Power Supply

To comprehend the working principles of the PoE switch power supply, let's examine the PoE network switch and PoE IP camera as an example to illustrate how the PoE switch power supply operates. Upon connecting a PoE IP camera to a PoE Ethernet switch, the following working process occurs:

Detection of PDs: Initially, the PoE switch delivers a minimal voltage through the port until it detects that the cable terminal connection corresponds to a PD that supports the IEEE802.3af standard. Typically, a 24.9kΩ resistor is employed in the PD equipment to verify compliance with the IEEE802.3af power supply standard. It is important to note that only active PoE network switches perform this check, while passive PoE network switches or injectors do not. The differences between active and passive PoE switches will be further illustrated here: Active vs. Passive PoE Switch: Which Should We Choose?

Classification of PoE Switch Power Supply Capability: After detecting the PD, the PoE switch supplies a voltage of 15-20V to the PD and determines its specific power requirement by measuring the current. The switch classifies the device into various types: Class 0, 1, 2, 3, 4, 5, 6, 7, and 8, based on the presence of a resistor, and provides the appropriate power accordingly.

Commencement of Power Supply: Once the Power over Ethernet classification is completed, the PSE device initiates power delivery to the PD device, starting from a low voltage that gradually ramps up to the full 48V DC within a configurable startup period (typically less than 15μs).

Normal Power Supply: Once the voltage reaches 48V, the PoE switch reliably and consistently provides a stable 48V DC power output to the PD.

Disconnection of PoE Switch Power Supply: The PoE switch swiftly (usually within 300-400ms) discontinues power supply and re-enters the PD detection procedure under the following circumstances:

• The PD is removed.

• The power consumption of the PD is overloaded or short-circuited.

• The total power consumed by the PDs is out of the power budget of the PoE-powered switch.

In these situations, the switch and PDs are protected, preventing any potential damage to non-PoE devices inadvertently connected to the PoE ports after the PDs are disconnected.

PoE Switch Power Supply Mode

The power supply mode between the PSE and PDs in a PoE switch can be categorized into three distinct modes:

Mode A

In this mode, the PoE switch supplies power to PDs through data pair 1-2 and pair 3-6. Pair 1-2 represents the positive polarity, while pair 3-6 represents the negative polarity.

Mode B

In Mode B, the PoE switch delivers power to PDs via pair 4-5 and pair 7-8. In 10BASE-T and 100BASE-T, these two pairs are not used for data transmission and are referred to as spare pairs in 10/100M PoE applications. Pair 4-5 represents the positive polarity, while pair 7-8 represents the negative polarity.

The primary distinction between Mode A and Mode B lies in the utilization of PINs, as depicted visually in the following diagram:

PSE devices can transmit power in two different modes: Mode A, also known as "endspan," where power is relayed through the data pairs, and Mode B, also known as "midspan," where power is relayed through the spare pairs. Compliant PSE devices are capable of supporting Mode A, Mode B, or both, while compliant PDs can work with both Mode A and Mode B. However, compatible PDs usually support Mode B only. Let's explore the working scenarios between switches and IP cameras based on these two modes.

4-pair Delivery

In this mode, power is delivered using all four pairs. Pairs 1-2 and 4-5 serve as the positive polarities, while pairs 3-6 and 7-8 act as the negative polarities.

The table below illustrates the three modes in two distinct network scenarios:

Please note that the Power over Ethernet (PoE) power supply mode is determined by the Power Sourcing Equipment (PSE). Both PoE switches and PoE injectors can act as PSE devices to provide power and data to Powered Devices (PDs). PoE Ethernet switches, commonly referred to as endspans (or endpoints according to IEEE 802.3af), typically utilize PoE mode A. On the other hand, PoE injectors (also known as midspan devices) function as intermediary devices between non-PoE switches and PDs, supporting only PoE mode B.

PoE Switch Power Supply Distance

PoE can transmit power up to 100 meters from the PSE to the PDs. However, the total length of Ethernet cabling is limited to 100 meters due to signal attenuation specified by Ethernet cabling standards. In the case of PoE switches, the maximum distance for power transmission is typically 100 meters. The actual PoE transmission distance may vary depending on the network cables used. For Cat5e, Cat6, Cat6a, and Cat7 cables, the maximum transmission distance is 100 meters. However, Cat8 cables, despite supporting 25/40 Base-T transmission speeds, have a reduced maximum transmission distance of only 30 meters.

PoE Switch Supply Voltages and Types

According to the IEEE 802.3 standard, PoE switches are categorized into four types, each associated with a specific supply voltage. The table below provides a breakdown of the supply voltage for each PoE switch type.

Conclusion

Power over Ethernet (PoE) technology plays a crucial role in the ongoing digital transformation. Understanding the power supply aspects of PoE switches is essential for ensuring the protection of both PoE and non-PoE devices. Familiarizing oneself with common issues and solutions related to PoE switch connections is also beneficial in preventing unnecessary time and financial resources from being wasted during the deployment of PoE networks. By staying informed and prepared, organizations can fully leverage the advantages of PoE technology and optimize their network infrastructure.

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. 

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 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.