6 min
Since its inception in 2003, Power over Ethernet (PoE) has significantly improved network operations from a time saving, cost saving, and functionality perspective. Over the last 20 years what started out as a system that facilitated the use of devices such as voice over IP (VOIP) systems is now capable of supporting surveillance network devices and even providing government organizations with increased connectivity. In this article, we’re going to take a look at what Power over Ethernet (PoE) is, how it works, its benefits, and some troubleshooting tips.
What is Power over Ethernet (POE)
Power over Ethernet (PoE) consists of technology that allows both data and power to be delivered via a single Ethernet cable. Without the need for multiple power supplies, it reduces the complexity of installations and helps create a clutter free network setup. The nature of PoE means it is perfect for connectivity to devices where power outlets are not available, such as wireless access points and surveillance cameras.
How Does Power over Ethernet Work?
There are two main factors which come into play when setting up a PoE system. The first is power sourcing equipment (PSE) and the second is the powered device (PD). Power sourcing equipment (PSE) serves as a power source, and the powered device (PD) relates to any piece of equipment that is able to use PoE technology to receive power and data via the same Ethernet cable.
Importance of the Power Supply
Two elements allow a PD to turn on using PoE - voltage & wattage. It is important to understand that the laws of physics dictate that voltage will drop over distance. Every PD will have a lower voltage threshold that needs to be achieved to turn on. Many Comnet PSUs have a voltage adjustment screw to increase the voltage at the source, this helps to negate voltage drop over longer RJ45 cable runs.
PoE Standards Explained: PoE vs PoE+ vs PoE++
According to the Institute of Electronic and Electronics Engineers (IEEE), there are four main types of PoE:
PoE (802.3af)
Introduced in 2003, this was the first type of PoE solution, with the Ethernet cable being split as follows: two wire pairs to transmit data, and two to deliver power, delivering up to 15.4W (watts) of power, equating to around 12.95W of “actual” power being transmitted to the devices.
PoE + (802.3at)
The second type of PoE is known as PoE +, with the main difference being the ability to output a higher power rating of 30W. It uses the same wiring setup as the standard PoE system, and power received by the connected devices is typically 25.5W.
PoE ++ (802.3bt Type 3)
Also known as 4PPoE (Four-Pair Power over Ethernet), this type uses four pairs in the Ethernet cable for both power and the delivery of data. Power output is 60W with PoE ++, and devices receiving power can expect to receive up to 51W of power.
PoE ++ (802.3bt Type 4)
The fourth type is similar to 4PPoE, however it has a much higher output level of 100W, meaning the connected device is able to receive around 71.3W of power.
Key Benefits of Using Power over Ethernet in Your Network
Simple Installation
Without the need for running separate power and data cables, PoE is simple to set up, and provides a tidier cable setup as a result.
Lower Costs
Both labor and time costs are dramatically reduced with a PoE system. Not only are less pieces of equipment required such as additional cables, networking cabling does not need to be installed by an electrician, saving additional labor costs. PoE systems are also more efficient which means lower running costs.
Safety
Due to its nature, a PoE system runs at a lower voltage which reduces the risk of overload and safety risks associated with working with higher voltage power systems.
Flexibility & Scalability
Components such as PoE switches allow devices to be added quickly and easily, meaning end users can scale and expand their network without the need to make significant changes to infrastructure.
Not having to rely on electrical outlets means that devices such as cameras and wireless access points can be positioned and repositioned easily.
How to Set Up Power over Ethernet Step By Step
Step 1: Ensure Device Compatibility
The first step is to make sure the devices you are using are all compatible with PoE.
*Note you can still connect a Non-PoE end device to a PoE switch - it will not damage the device but only data will be passed.
Step 2: Choose Between PoE Injector or PoE Switch
You then need to select a suitable PoE switch that has enough ports to connect your devices to, or alternatively use a PoE injector. It is important to remember to check if the PoE switch or injector can provide enough power to the devices.
Step 3: Connect the Network
Connect the PoE switch (or injector) to your current network switch or router using an Ethernet cable.
Step 4: Turn on Power to All Devices
Power up all devices in preparation for a system test.
Step 5: Test the Setup
Test the system for functionality, and troubleshoot any issues according to our tips below.
Common Power over Ethernet Issues and Troubleshooting Tips
You may occasionally encounter issues with your PoE setup, so here are some of the common problems and how to troubleshoot them:
Lack of Power
Troubleshooting Tips:
- Check cable quality and always use high quality Ethernet cables
- Ensure the devices you are using are PoE compatible
- Assess whether there is sufficient power to support all your connected devices
- Check the power supply is set to the correct voltage (802.3af = 48VDC // 802.3at & 802.3bt = 50-57VDC)
*Note Comnet PSUs have a simple turn screw on the front to adjust voltage.
Intermittent Connectivity
Troubleshooting Tips:
- Check all cables for damaged or loose connections
- Use a network cable tester to assess whether the cable is faulty
- Upgrade cables to mitigate any ongoing connection issues
Network Errors
Troubleshooting Tips:
- Check the switch configuration and make sure the PoE settings are correct
- Update firmware
- Ensure the PoE switch is compatible
Conclusion
PoE has been, and continues to be an integral part of network communications across all industries from healthcare to the military. The ability to deliver both data and power via Ethernet has been revolutionary in creating a safer, more reliable, and cost effective networking solution for organizations. With various PoE types providing up to 71.3W, the use cases continue to grow. At Comnet, we are proud to say our products are fully TAA and NDAA compliant, and made in the USA. Our products are certified in extreme temperatures, making us a company you can rely on when you need your systems and devices to simply just work.
For more information on our products please e-mail us at: comnetsales@acresecurity.com.
