Berger & Schroter PRO X7 Operating Instructions Manual page 21

5-3 Pin Lock Mode
Principle:
In the Pin Lock Scan mode, the point D may be isolated from a number
of points in the background out and keep only the distance d1 to the
point.
So as to achieve the automatic locking flagpole distance.
The other goals were shielded behind the flagpole.
Pin Lock
21