The LED control connection is a single wire and is specified as a "Dry Contact (N.O.)" input.
If you run your reader off 5V then you can connect it directly to the arduino. If you run it off anything else then you need a transistor to protect the arduino output from the high voltage.
It looks like you have a Weagand reader do you know how to interface that?
Then I'll see what the reader does with the pin high and with the pin low
My guess is it will be red when it's high and green when it is low. To get yellow waggle the bit up and down.
Nice keypad. I have a HID ProxyPoint 6005 and I have no clue how to program it to my Arduino Uno. It has 2 wires for led's, one for red and one for green. It also has wires like data0/data, data1/clock, beep, and power. How do I get mine started?