Control.com - Nerds in Control

We need to drive a relay at approximately 800 meters distance. We don't have any spare cable pair. Is it possible to drive the relay with the help of wireless communication? If yes, then plz tell me where I can get information about this.

You may want to consider Omnex
(http://www.omnexcontrols.com/products/industrial/).

They offer small one way systems (one analog, 2 digital) and large 2 way systems (analog, digital and serial)

Rob Barrese
Dofasco

http://www.phoenixcon.com/wireless

1 way i/o radio

Yes, there are numerous ways to do this. But 800 meters is a LONG way, so make sure your supplier(s) know what they are doing.

Here's a partial list (in alphabetical order) of industrial wireless suppliers. For what it's worth, my first phone call would be to be to Banner to ask about their SureCross product. My second would be to Phoenix Contact.

Banner http://www.bannerengineering.com/surecross/
Data-Linc
Digi
El pro
Esteem
Firetide
MaxStream
Phoenix Contact
RadioLinx (ProSoft)
Solecteck

-James Ingraham
Sage Automation, Inc.

What is it with this old 60's /70's Double and Single Pair Cable Usages: "thats such wayyy old School thinking" and a answer to your question "thats a easy one" Wireless Ethernet Modem with a web-Enabled relay thru ethernet:
Complete web Server enabled Ethernet relays:

Rob,

Radio is fine for line-of-sight but since you already have some cables check out "Cable Concentrator" These allow you to multiplex many signals on to one pair of wires for exsmple 8 discrete inputs at one end drive 8 discrete outputs at the other. You can also mix analog and discrete signals sending both ways.

I have used Moore Industries previously to make a distributed I/O system with very good results.

Roy

We offer industrial data communication equipment (wire and wireless) so it is likely that we have a solution that fits your exact need.

We have short, medium and long range wireless modems and I/O extender/multiplexers.
Our LCM100 is a powerline modem http://www.data-linc.com/powerline.htm that transmits data over existing lines without interfering nor being interfered with. You can use our Selection Guide page to match up our products to your needs. You may also contact an application engineer for a no-obligation consultation at info@data-linc.com or call 425-882-2206 Pacific Coast Time: business hours 7:30 a.m. to 5 p.m.