Power over Ethernet Pinout
Introduction:
Power over Ethernet (PoE) is a technology that allows for the transmission of both data and power over a standard Ethernet cable. This eliminates the need for separate power cables and simplifies the installation and management of network devices. In this article, we will discuss the pinout of a Power over Ethernet (PoE) cable and its various levels.
1. Category of PoE:
There are currently two categories of PoE – IEEE 802.3af and IEEE 802.3at. The former can deliver up to 15.4 watts of power, while the latter can deliver up to 30 watts. Both categories use the same pinout configuration.
2. Pinout Configuration:
A Power over Ethernet cable uses all four pairs of wires within an Ethernet cable. The pinout configuration follows the 568B standard, with the power being supplied over spare wires. The pinout for Ethernet data transmission remains the same – pins 1, 2, 3, and 6 are used for data transmission. The power is transmitted over pins 4, 5, 7, and 8.
3. Pinout Assignment:
In a PoE cable, pins 1 and 2 carry the positive (+) voltage, while pins 3 and 6 carry the negative (-) voltage. The positive and negative lines are often referred to as V+ and V-, respectively. Pins 4 and 5 are not used for Ethernet data transmission and carry unused power. Pins 7 and 8 are also not used for data transmission and can be used for additional power delivery in IEEE 802.3at.
4. Power Sourcing Equipment (PSE) and Powered Device (PD):
In a PoE network, there are two main components – Power Sourcing Equipment (PSE) and Powered Device (PD). The PSE is responsible for injecting power, while the PD is the device receiving power. The PSE can be a PoE switch or a PoE injector, while the PD can be any network device such as IP cameras, wireless access points, or VoIP phones.
5. Compatibility:
It is important to ensure that the PSE and PD are compatible to prevent any damage to the devices. IEEE 802.3af PSEs are backward compatible with IEEE 802.3at PDs, but not vice versa. Therefore, if you have an IEEE 802.3at PSE, it can power both IEEE 802.3af and IEEE 802.3at PDs. However, an IEEE 802.3af PSE can only power IEEE 802.3af PDs.
Conclusion:
Power over Ethernet is a convenient technology that simplifies the installation and management of network devices by transmitting both data and power over a single Ethernet cable. Understanding the pinout configuration is essential for ensuring proper compatibility and safe implementation of PoE. Whether you are setting up a security system or expanding your network infrastructure, Power over Ethernet offers a reliable and efficient solution.
