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4-Channel Power-over-Ethernet Midspan Injector www.freetronics.com/poe-injector-4ch
Getting Started: 4-Channel PoE Midspan Injector The Freetronics 4-Channel PoE Midspan Injector accepts an input voltage between 7V and 24V, either AC or DC, and rectifies it to DC before injecting it onto the spare pairs in the network cable that are not used by 10/100base-T Ethernet. DC+ is connected to Ethernet pins 4 and 5, while DC- is connected to Ethernet pins 7 and 8. Power is only injected "downstream" to devices connected to your network segments: it is not connected back to your Ethernet switch, which is isolated from pins 4, 5, 7, and 8 inside the Midspan Injector to prevent any damage to upstream network equipment. Warning: This injector does NOT provide 48V 802.3af/at standardscompliant Power-over-Ethernet for use with commercial devices. It is only for use with devices capable of operating off the voltage you connect to it, such as the Freetronics Ethernet Shield with PoE Support (www.freetronics.com/ ethernet-shield). For detailed information on Power-over-Ethernet schemes and connection methods please see www.freetronics.com/poe.
Installation And Testing 1. Connect an appropriate power supply between 7V and 24V (depending on the specifications of your Powered Device, or PD) to the 2.1mm power jack on your Midspan Injector. Verify that the "Power" LED illuminates.
2.
Disconnect a LAN cable from one port of your Ethernet switch, and connect it instead into one of the "Device" ports of your Midspan Injector.
3.
Use a short Ethernet patch lead or spare Ethernet cable to connect the corresponding "Switch" socket on your Midspan Injector to the port of your Ethernet switch.
4.
Connect a Powered Device such as an Arduino fitted with a Freetronics Ethernet Shield to the other end of that network segment.
5. Verify that your Powered Device is receiving power via the LAN and has network connectivity. 6. Repeat steps 1 through 5 for each network segment that you wish to power.
Online Resources There's a wealth of information, sketches and libraries out on the internet for all things Arduino related. If there's a useful function, IC or shield there is likely to be some example code or a library to support it. And it's being added to almost daily as people like yourself create new solutions and share their projects and code to suit. The official Arduino website includes a wealth of information including tutorials, a language reference, projects, and examples. Official Arduino site www.arduino.cc Arduino discussion forum
www.arduino.cc/cgi-bin/yabb2/YaBB.pl
Freetronics resources page
www.freetronics.com/resources
Freeduino knowledgebase
www.freeduino.org
IRC channel Network: irc.freenode.net. Channel: #arduino A Google search for "arduino projects", "arduino code" or "arduino examples" is recommended too.
Arduino Books Getting Started With Arduino by Massimo Banzi (O'Reilly) A gentle introduction to using your Arduino for the first time: how to connect it up, load programs onto it, and do some basic experiments to give you a feel for how it works. Great introduction for the first-time Arduino user. 128 pages.
www.oreilly.com/pub/pr/2115 Practical Arduino by Jonathan Oxer and Hugh Blemings (Apress) Taking you far beyond the basics, this book blends theory and practice by using example projects to illustrate some of the more advanced things you can do with Arduino and how to apply those same concepts to your own designs. After working through this book you'll be very confident designing and building your own Arduino creations. 445 pages.
www.practicalarduino.com
Midspan Injector Features Input Voltage Output Voltage Maximum Current DC+ Output DC- Output Ports Supported
Specifications 7-24V, either AC or DC 7-24V DC 1.5A total across all ports Ethernet pins 4 and 5 Ethernet pins 7 and 8 4
Power-over-Ethernet Basics All PoE schemes require two essential elements: "Power Sourcing Equipment" (or "PSE") located inside or near your Ethernet switch to "inject" power onto the network cable, and the "Powered Device" (or "PD") to extract and use the power. Your 4-Channel Midspan Injector fills the role of the Power Sourcing Equipment, making power available on selected network segments to devices configured to use it.
A more detailed explanation of PoE can be found on the Freetronics website at www.freetronics.com/poe. For supplying power to an Arduino connected to a Freetronics Ethernet Shield (www.freetronics.com/ethernet-shield) the recommended input voltage is 7 to 12V. Running at that voltage will allow your Ethernet shield to pass the supplied power directly through to your Arduino for regulation to 5V simply by placing jumpers across the PoE header on the shield. More information is provided in the Getting Started guide provided with the Ethernet Shield. By fitting your Ethernet shield with a PoE Regulator 24V daughter-board (www.freetronics.com/poe-regulator-24v) you can supply up to 24V to the network segment via the midspan injector. The PoE Regulator 24V pre-regulates the supplied voltage down to 12V for further regulation to 5V by the Arduino's on-board voltage regulator.
About Freetronics Freetronics is an Australian company created by Jonathan Oxer and Marc Alexander to provide cheap and easy access to hardware, parts, and products related to Arduino projects and the Practical Arduino book. Learn more at www.freetronics.com. Follow us on Twitter at twitter.com/freetronics.
