Fert spreader auto shut off

[Bobthebuilder]

After a blunder I’ve managed to wipe the implement settings off my amatron box [emoji849] got it working again of sorts but not quite shutting off/ starting in the correct place on headland in auto mode, anyone know where these 2 measurements refer to on a mounted machine

 

[Arrow1]

From the manual,
Under X1 enter the distance between the coupling point and application point.
For fertilizer spreaders application point is centre point of spreading discs.
X2 distance from coupling point and axle,not required on mounted machine.
If I get a chance I will check our machine which is a ZAV.