MG811 CO2 sensor wiring

Other Hardware Sensors
1

Hello. I have a CO2 sensor with 4 pins. VCC, DOUT,AOUT, GND. Where does the VCC, AOUT, and DOUT wire to? I found no wiring manual when I purchased this sensor off of ebay. I have gone to this link where someone is using the same sensor. However, I don't follow his path considering the third pin (red) isnt going anywhere. It just leads out and stops. http://middlewaresensing.files.wordpress.com/2010/08/100708144455.png

Can anyone spell it out clearly for me please?

GND- wires to GROUND
Vcc- Wires to ?
AOUT- Wires to?
DOUT - Wires to?

Your help is most appreciated. Thank you

2

vcc is voltage. Try it with 5v.
aout is probably analog out.
dout is probably digital out.

You would probably only use one of dout or aout so it makes sense one is left hanging.