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

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.