The loop impedance measurement ZL-PE does not work if a 2-pole adapter is used?

This error message appears:

Cause: If RCD tripping is suppressed (setting DC-H or DC-L), the presence of a neutral is necessary.

Solution: Make a 3-pole adapter out of the 2-pole adapter (connect an additional string for the neutral conductor)
or
change to the "solid shaft" setting.

Auxiliary view: Next to the 2-pole adapter is the marking "AC", which stands for alternating current. In this context, this means that "full wave" must be set.