Proximity sensor devise HELP !!!

[slimmy123]

Hi all im new to electro tech and this is my first post,

im in the process of setting up a alarm system were i plan on installing a load of sensors on the ceiling around my warehouse for stock management. Each sensor would relay a signal back to a panel (if possible wirelessly).
On the panel i would like a red and green light for each sensor, when there is nothing in the way of the sensor the light would be permenantly on green and when something goes in the way of the sensor the green light will go off and the red light will switch on then as soon as the object moves out the way the green light will come back on and red off.
I thought about a obstruction sensor similar to what is installed on a garage door but i cant have a sensor on the floor due to trip hazzard so now i think a proximity sensor of some sort. i would like the sensor to only pick up things directly below it (upto 2.5 metres) and not have a spread out range such as a house alarm motion sensor as i only want it to pick up the pallet below and not the one next to it!

Do you know of any items that could make this happen?
Also any other help would be realy helpfull as i dont realy know alot about sensors or electronics for that matter either!!!

Kind regards

 

[CafeLogic]

Sharp makes a line of relatively inexpensive infrared proximity sensors. You could also use sonar. If you don't know electronics, but you can program, you can try phidgets: Phidgets Inc. - Unique and Easy to Use USB Interfaces

 

[CafeLogic]

On a side, RFID tags are all the rage right now for tracking pallets.

 

[crutschow]

You may be able to use a Diffuse Reflective IR Sensor such as this. They have a maximum range of 3m.

But they are not wireless. For that you could use an industrial wireless network to connect to the sensors such as one of these.

Setting these up would likely require a professional since it would be rather difficult for a newbee.

 

[slimmy123]

cheers for the replys ye think im gonna have to go to a design company for this one bit to complex for me!!!