[Difinity]

Hi,

I've rebuilt my old wood routed track into a small spare room, which necessitates redoing the timing system.
I know the Audino Uno connection to the PC is ok and working, but am unsure about wiring up the sensors. Can anybody help with what should be a simple question?

I have replaced separate IR LEDs and sensors with an intrack combined unit (Jaycar ZD1901 photo interrupters).
I need help identifying which connections to attach the old wires to as it has both LED and sensors in the one unit. Connections are: 
Cathode (K); Anode (A) on one side, and Collector © and Emmitter (E) on the other. I also need advice as to which of these should have the resistor added.

The Audino sketch and connection is already set up, so should be ok if I wire the hardware the right way.
Previous setup used twin IR LEDs on a gantry, and single sensors in track. I've gone for this combined solution now due to a lack of space above the track (a gantry will hinder marshalling and means the timing is in the wrong (less useful) sector of the track.

Track is a now a 12m 3 lane 3 level twister, fitted into a 2.4 * 1.8m space.

many thanks
Difinity