IPIQ: Using PoE to Simplify Home Automation, AV and Security Installations
IP devices require both power and network connections, which traditionally are run separately. However, it is becoming more and more common for devices to support Power-over-Ethernet (PoE), which offers a method for delivering both power and network connectivity over a single cable.
Today, IP Phone Systems, Wireless Access Points, Security Cameras, Motion Detectors, Touch Panels, Thermostats, and Lighting Controls are all available with PoE support, making it an attractive option for home automation, AV and security installers. PoE offers installers a tremendous advantage in delivering flexible, reliable and cost effective solutions.
What is PoE?
PoE is the delivery of low voltage DC power over the same media used for data transmission on CAT5, CAT5e or CAT6 Ethernet cabling. There are three widely used PoE standards:
• Legacy PoE—provides a full 48 VDC and 48 Watts at all times
• 802.3af—provides 48 VDC with a maximum of 15.4 Watts
• 802.3at (also known as PoE+ or PoE plus)—provides 48 VDC with a maximum of 25.5 Watts and is backwards compatible with 802.3af devices.
It is important to note that 802.3af/at source devices (i.e. Switches, Midspans, and Power Injectors) are only compatible with 802.3af/at client devices and will not supply power to Legacy client devices. This is because 802.3af/at requires two-way communication between the source and client device as part of the 802.3af/at standard. However, most 802.3af and 802.3at client devices are backwards compliant with Legacy PoE sources. In planning an installation and selecting which products to use, it’s also important to recognize that an 802.3af client can work with an 802.3at source, while an 802.3at client can only work with an 802.3af source if the client’s maximum power usage does not exceed 15.4 Watts.
Why Use PoE?
PoE is a rather flexible and cost-effective way to provide data and power to a remote location, or to simply streamline an AV, control, and/or security installation. Some of the benefits include:
Related story: IPIQ: The Connected Home