The power and the glory


Many years ago I tested a printer adapter that allowed printing across power mains – specifically the same electric ring circuit. It didn’t work very well I have to say. Not much point if you can’t have printers shared in another room. Well things have moved on dramatically since then. Ethernet over power (EOP) devices or as some people call them Powerline or Homeplug devices (I would have suggested EtherPower but hey everyone has ideas) – are popping up everywhere with various functionality.

Where would I use such a device and what does it do (I hear you say) ? Well here are some examples – with a little explanation first.

The basic idea of these devices is to transmit ethernet traffic over the mains at various speeds depending on the products used and the quality of the wiring. Various suppliers have differing speed options including Devolo whose AV200 MB devices I’ll mention later. So you will have an ethernet RJ45 socket on the device and in some cases a USB socket also. The Devolo and other ranges of compatible devices required the setting of a password on the devices to prevent eavesdropping on traffic on the mains. This is acchieved by connecting a unit to the mains and with an ethernet cable to a pc and using the supplied software set a common password on all the EOP devices that you trust in your network. Thats basically it. Plug an ethernet device into one socked and on into another and they can communicate as though they were plugged into an ethernet network.

So where would you use them ?

How about connect a portable to a non wireless router ? How about from every room in you house for sharing internet access ? How about between two buildings like a home office and main house ? How about for going beyond the ethernet cable length distance between two devices? How about for creating a network in a room in about 5 minutes !

HomePlug’s standard has physical advantages over its competition, too. It doesn’t require special wiring like Ethernet networks do, and it can do something that wireless networks can’t: communicate between the attic and the basement of a four-story house. Wireless networks have a working range of about 150 feet in the case of the earlier lower speed and , and the connections get slower the farther the wireless receiver is from its base station. HomePlug networks, on the other hand, have a range of about 1,000 feet of power cable.

What about security ?

As I mentioned a password needs to be set – most devices have a default – I recommend changing it asap. In the Devolo case you also need physical access to the device to get the unique code that is marked on it for configuration purposes.

How do I actually set one up ?

Once the same passwords are set on a pair or more than devices – you just plug in the ethernet devices – Pcs – routers – printers and as long as they have an IP address set or are getting an address via DHCP – you are ready to go.

I can recommend Devolo and their range of devices. Recently I replaced a pair of 14MB Devolo units with the AV200MB versions and I have to say the performance is red hot. I’ve used them for linking a number of machines to a redundant router for adsl access. As always monitoring has a place in the technologies that I use. In this case the EOP approach makes it much easier to install climate and temperature monitoring where ethernet linkage over conventional cabling would prove to costly or difficult !!! It reduces the need for cabling and speeds up installation.

Why not just use wireless ?

Well – I have seen a number of circumstances where wireless wasn’t appropriate or just didn’t work. The EOP devices are an extra option to help you in your quest to link up devices which may or may not be wireless capable.

BTW – The Power and the Glory is the title of a Horslips (Irish Celtic Rock Band) song from the Album “Book of Invasions”.
Get the album and it will “blow your lugs off” as the Horslips publicity used to say.