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 Power Utilite (Headless) Using Power Over Ethernet (POE) 
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Joined: Mon Jan 09, 2012 3:16 am
Posts: 351
Post Power Utilite (Headless) Using Power Over Ethernet (POE)
Overview

Many devices are now equipped to use Power Over Ethernet (POE) as their power source. Such devices include VOIP telephones, iP cameras, wireless access points, and a growing variety of embedded devices. Utilite, due to its miserly power requirements, is an ideal candidate for headless POE operation.



Some POE Basics

The most common forms of Power over Ethernet are specified by IEEE Standard 802.3. There are 2 prevalent variants of IEEE802.3 POE which are Type 1 Low Power covered by IEEE 802.3af (2003) and the newer Type 2 High Power covered by IEEE 802.3at (2009).

Any item of equipment used in POE applications can be classified as either Power Sourcing Equipment (PSE) or a Powered Device (PD). As their names imply, PSE's inject power into the systems and PDs use that power.

Some specfics about the POE variants are included in the table shown below.

Attachment:
POE Data.jpg
POE Data.jpg [ 132.64 KiB | Viewed 5619 times ]


Since Utilite typically draws less than 10 watts of power, it is suitable for use with both 802.3af low power and 802.3at high power systems.



The System

The Utilite POE sysytem I am testing is detailed in the following block diagram. Note that Utilite is operating in a headless configuration and is controlled using VNC via a Compulab fitPC3 Pro running Windows 7.

For simplicity, I elected to run Utilite in a headless configuration using a Compulab fit-Headless HDMI monitor adapter. This approach gives good headless results and does not require any changes to my Ubuntu Linux OS.

Attachment:
Utilite POE Block Diagram.jpg
Utilite POE Block Diagram.jpg [ 86.55 KiB | Viewed 5619 times ]


Last edited by hassellbear on Mon Oct 20, 2014 11:14 pm, edited 7 times in total.



Sun Sep 21, 2014 6:18 pm
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Joined: Mon Jan 09, 2012 3:16 am
Posts: 351
Post Re: Power Utilite (Headless) Using Power Over Ethernet (POE)
Hardware

The hardware used in this project can be broadly broken into 3 categories. These are Power Sourcing Equipment, Powered Devices/VNC Server, and VNC Client.


1. Power Sourcing Equipment

A. Black Box LPJ024-FM, 24 port, 802.3af POE injector

Attachment:
Blck Box POE Injector.jpg
Blck Box POE Injector.jpg [ 14.02 KiB | Viewed 5619 times ]



2. Powered Devices/VNC Server

A. Compulab Utilite Pro running Ubuntu Linux
B. Compulab fit-Headless HDMI monitor emulator
C. Intellinet 560443, POE+ Spliter (IEEE 802.3at)
D. POE power cable for Utilite

Attachment:
Utilite POE Client Equipment.jpg
Utilite POE Client Equipment.jpg [ 112.72 KiB | Viewed 5619 times ]


Note: The Intellinet POE+ Splitter accepts a RJ45 combined data + power input and has seperate data only and power only outputs. It has switchable DC output voltages which include 5 VDC, 7.5 VDC, 9 VDC, and 12 VDC. It conforms to IEEE 802.3at specifications and has an output power rating of 25.4 watts - which is in excess of Utilite's power requirements.


3. VNC Client

A. Compulab fitPC3 Pro running Windows 7 32 bit

Attachment:
fitPC3.jpg
fitPC3.jpg [ 108.21 KiB | Viewed 5619 times ]


Last edited by hassellbear on Mon Oct 20, 2014 10:28 pm, edited 8 times in total.



Sun Sep 21, 2014 6:55 pm
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Joined: Mon Jan 09, 2012 3:16 am
Posts: 351
Post Re: Power Utilite (Headless) Using Power Over Ethernet (POE)
Assembled Test System

Here is the assembled test system. It was compressed using short cable so that everything would fit in 1 picture. Obviously, in a real world application the POE Data/Power Cable would be much longer - up to 100 meters. I did make one change - I replaced the 24 port POE Injector with a single port injector. The 24 port was a loaner and also a bit of overkill.

Attachment:
Utilite POE Working System Small.jpg
Utilite POE Working System Small.jpg [ 246.74 KiB | Viewed 5619 times ]




Software

1. Headless Utilite Linux VNC Server

Install X11VNC on Utilite (available in Ubuntu Repository)

Configure X11VNC to start on bootup by adding the script x11vnc.conf to /etc/init/. Create x11vnc.conf using your favorite text editor. Include the following commands in the file:

> start on login-session-start
> script
> /usr/bin/x11vnc -xkb -noxrecord -noxfixes -noxdamage -auth /var/run/lightdm/root/:0 -display :0 -passwd "Your VNC Password Goes Here" -forever -bg -o /var/log/x11vnc.log
> end script


Note: The script listed above uses the default port 5900.



2. VNC Client

I am using RealVNC installed on fitPC3 Pro running Windows 7, 32 bit

Attachment:
RealVNC logo.png
RealVNC logo.png [ 4.86 KiB | Viewed 5619 times ]



Results

Utilite operates perfectly in a headless configuration using Power Over Ethernet instead of an adapter as the power source. The following picture shows my fitPC3 connected to the headless Utilite via VNC.

Attachment:
Utilite POE Screenshot.jpg
Utilite POE Screenshot.jpg [ 219.14 KiB | Viewed 5619 times ]


Conclusions

1. If you have a need for operating a headless Utilite in a physical location where a physical ethernet connection is available but mains power is not availalble, then POE may offer an alternative provided the ethernet cabling is adequate and the run isnt too long.

2. For a new headless Utilite installation where both data and power cabling must be run, POE may provide a cost savings by eliminating the need to run power cabling.

3. Utilite again demonstrates its versatility in fullfilling many different roles.


Sun Sep 21, 2014 7:16 pm
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