Posts Tagged ‘POE’

Power Over Ethernet (POE) Explained by Veracity

Tuesday, December 16th, 2008

Power Over Ethernet brings some great additional benefits to the application POE experts Veracityof IP security devices such as network cameras.

Essentially, you can power the camera (or other network device) via the ethernet data cable:

  • a single cost-effective network cable to each device
  • safe low-voltage supply
  • easily extend your network
  • no need for skilled electrical installation labour
  • a single device POE mid-span extension
  • multiple devices via a POE switch
  • the ability to ‘reach’ 100m or more from your existing network
  • 802.3 POE standards allow common solutions for many devices
  • even devices that do not have POE built-in can be used with POE supplies (by use of an Active Splitter at the device end)

We take a lot of calls about the use of POE with IP CCTV and are aware that people find some of the concepts a bit tricky.

Veracity have just produced some really helpful white papers to explain power over ethernet technology and its application:

“Power Without the Struggle” – the benefits of POE technology and how to take full advantage of them …

“POE Explained” – POE concepts through to the latest 802.3at ‘POE Plus’ solutions …

Veracity’s OUTREACH & OUTSOURCE solutions enable you to extend POE beyond 100m.

These new guides from Veracity are written in plain English with helpful graphics and diagrams to aid your understanding. We recommend you take a look.

use-IP Ltd are Authorised Partners of Veracity.

You can find their range of POE products in our POE shop.

Power Over Ethernet

Thursday, November 27th, 2008

Power over Ethernet (POE) allows you to very simply install network cameras (or other network devices such as VOIP phones) with just a single network cable.

We get a lot of queries about POE, so we’ll try to give you a quickand simple explanation:

An ethernet network is the standard format of network cabling that you use to connect your networked and other devices.

The cables used are commonly known as Cat5 cable (other variants such as Cat5e and Cat6 are available).

The plugs on the ends of the network cables are terminated in RJ45 connectors.

Each Cat5 network cable contains four pairs of cable cores, all of these cores are terminated in the RJ45 plugs, but only two of the pairs are actually used for the transmit and receive signals used by the network for data transmission.

This means that there are two pairs of spare cable cores available within every network cable.

Quite simply these can be used to carry power, electricity, volts & amps to devices on the network.

There’s an IEEE standard governing the proper format and use of Power over ethernet, and the basic version of this is the 802.3af standard. This standard governs things such as the configuration and use of the spare cores and the voltage used being common in all 802.3af compliant devices (nominally 48 volts DC). This relatively high voltage is used to enable the power feed to be useful over relatively long distances – up to 100m. If a lower voltage was used, the voltage drop caused by the cable length might render the even lower voltage arriving at the far end useless for powering the camera.

So, you can take a device known as a poe power injector and place this at the source end (PC, control room …) and route your network cable through the power injector on its route to the camera.

At the camera end, if the camera is a POE enabled device (has 802.3af compliant POE built-in) you can plug the far end of the network cable directly into the rear of the camera and the internal camera circuitry will split-out from the network cable the power that it needs to operate. In this way just a single network cable is all that is required to both feed power to the camera and to take the IP video signal away from the camera and back to the PC or other recording device.

This Power Over ethernet solution makes for really simple low-voltage installations without the need for a specialist electrical installation contractor, or the requirement for mains or other power cables. Hence, you save not only labour costs but also the cost of a second copper cable.

If the camera or network device does not have built-in POE compatibility, it is still possible to use Power over Ethernet by deploying a device called an Active Splitter at the camera end of the network cabel. An active splitter (as the name implies) is simly an electronic gadget which splits the power and data signals from the one combined network cable to the two cables that a non-POE device requires; one cat5 for data, one power for the camera supply. NB if you are using a splitter be sure to select a device which is able to transform from the 48V carrier signal used in POE down to the correct voltage for the camera you are using (likely to be 3.3V, 5V, 9V, 12V or similar) and is able to present the power in the correct physical format to plug into the rear of the camera e.g. 4.5mm barrel connector.

So, as you can see from the above, the basics of power over ethernet are simple, but there are a few potential pitfalls to catch out the unwary. If you need any help with selecting the correct POE devices for your application please just give us a call.

use-IP Ltd supply a range of POE devices.

Further explanation of Power Over Ethernet


Veracity – truly innovative IP network products

Friday, June 20th, 2008

HGHWIRE co-ax converter pair

Veracity manufacture a range of innovative products which enable you to extend your network reach, use Power Over Ethernet (POE), or utilise pre-existing co-axial CCTV cables for IP networking:

CAMSWITCH – a rugged, 4-port, POE, network switch

HIGHWIRE – enables you to utilise existing co-ax cable as a 100Mbit network for cameras or other IP devices

OUTREACH – stretches your network’s reach in 100m steps (with POE) up to 500m

TIMENET– provides an NTP (Network Time Protocol) device on your network to synchronise your devices

OUTSOURCE – is a POE midspan device to inject power onto your network cables for POE supply to IP devices

OUTBREAK – is a POE splitter, which will separate the power and data cables at the device to allow devices that do not have POE functionality built-in to utilise single cable POE supplies

We have now added the full range of Veracity products into our webshop.