Help wire garage roller door safety sensor

Hi,

I need to install a safety sensor to my roller shutter garage door.

I have had a look at the control box and the circuit is as follows:

1) Not defined
2) Not defined

(both of above connected to each other) by small jump wire

3) Start
4) Start

(These have the door button wires going into each)

5) 12v dc
6) 12 v dc

(nothing going into these at the moment)

7)
8)
9)

(all

crystalball.jpg

Make, model & current controls would be helpful, or you could just instal a motion sensor that cuts the power to the door if someone is in close proximity, but that is likely to be more troublesome with false calls.