PoE for Network-Attached Devices

Door Access Control, IP Camera Systems, IP PA Systems use PoE

Power over Ethernet (PoE) is the easiest way to provide power to many network-attached devices such as IP camerasdoor access control systems, and IP paging and Intercom systems.

The network cable transfers both data and power to the device, making installation very simple.  The network cable includes up to eight wires. The data uses one set of wires, while the power uses another set of wires in the network cable.

This article describes how access control systems, IP Camera Systems, and IP paging systems utilize power over Ethernet (PoE)

Network-Attached Devices Ilustration
Network-Attached Devices Illustration

How PoE is Provided

Network switches with PoE capability and network power injectors are used to add power to network-attached devices. There are several standards that define the voltage, current, and signals in the network cable. Network switches and power injectors that conform to the PoE (802.3af) standard provide 12.95W to the device. This is usually enough to power most IP cameras.

Some PTZ cameras, access control systems, and other network devices require higher power than 12.95 Watts. You can also select network switches that conform to PoE+(802.3at). They provide up to 25.5W to the device. Switches that support PoE++(802.3bt type 3) support up to 51 W while 802.3bt Type 4 switches support up to 71 W.

PoE is easy to implement using a network switch, but be careful about the specifications of the switch. Some network switches with multiple ports have a maximum power budget. This means that the required power may not be available on all ports. It’s best to select a switch that provides maximum power to all the ports.

For more details about PoE, read our article, How Power Over Ethernet Works.

PoE for IP Camera Systems

Almost all IP cameras can be powered by PoE. But there are some exceptions. PTZ cameras that operate in cold environments can require additional power to support the heaters in the camera system. There are also high-performance long-range cameras that include multiple camera systems, long-distance illumination, and high-performance pan-tilt mechanisms that require separate power.

Specialized PoE switches can also be used outdoors. These switches must be placed inside of enclosures to protect them from the elements but they are ruggedized to operate at wider temperature ranges. The article Industrial PoE switches: What you should know about them, provides more information.

PoE for Door Access Control

The latest access control systems are network-attached. The network is connected to the controller, which is either incorporated in the reader (reader-controller) or is a separate box (like the Hartmann access control system).

The power required by the access control system is determined by the type of electric lock, the type of relay in the reader, and the power available from PoE.

The IP readers and controllers are powered over the network (PoE) and supply 12 VDC to power electric locks. Electric strikes require less power than magnetic locks. The magnetic locks also cause current surges as they are energized. This power surge requires a higher rated relay. The Isonas reader-controller uses a solid-state relay so it can’t handle the current surge. Door access controllers that include reed-relays can support the mag locks.

The Isonas reader-controller uses the power provided through the RJ45 network connection. The electric lock is connected to the pigtail from the Isonas reader. The pigtail includes 12 VDC power and a relay connection that energizes the electric lock. The Isonas reader-controller can provide power to strikes as long as they don’t use more than 400mA of current.

Isonas access control system diagram
Isonas access control system diagram

The Hartmann access control system includes a network attached controller. The electric lock connects to the controller. The wires contain the power and the relay control for the electric lock. The controller includes a reed relay that can provide more power than the Isonas reader-controller.

Hartmann access control system diagram
Hartmann access control system diagram

Some access control readers, such as the pro-series biometric reader-controllers require a power splitter. The network is connected to one side of the splitter and the other side includes a standard network connection and a separate power plug (that splits off the power for the reader-controller).

PoE for IP Paging and Intercoms

Network-attached PA systems and intercoms use PoE to simplify installation. Small amplifiers can be placed wherever you have a network drop. No need for long speaker wire connections from a large central amplifier. TalkMaster software runs on your PC, manages the system, and provides digital voice quality sound wherever you need it.

Intercoms allow you to communicate to a specific room, or any location you have a network connection.

Power Over Ethernet Systems Summary

PoE is used by IP camera systems, door access control systems, and IP paging systems. The access control systems use PoE to provide power to the readers, controllers and the electric locks. PoE makes the implementation of these network-attached systems very easy. It is essential that you know the power requirements of the IP devices that are attached to a power over Ethernet system.

If you would like help using PoE please contact us at 800-431-1658 in the USA, or at 914-944-3425 in the USA, or just use our contact form.