Could anyone please explain the property that needs to be set to prevent arrows from being connected to a node (box in this case) other than at the pre-defined anchor points.

I have 2 boxes with 12 anchor points (allowing both incoming and outgoing) defined each.  I then create an arrow by dragging from an anchor point on one box to an anchor point on the 2nd box.  The arrow is created with connections on the pre-defined anchor points.  However, I can then drag the end point of the arrow and drop it onto a different location on the destination box and it quite happily attaches to the box at that point which does not have an anchor point defined (e.g. in the middle) rather than springing onto the nearest anchor point.

Any help would be much appreciated.

Thanks Iva ... exactly what I needed.