Haas Alarm: 603 (L) NON-MONOTONOUS PQ BLOCKS IN Z – The path defined by PQ was not monotonic in the Z-axis. A monotonic Path is one that does not change direction starting from the first motion block. The control is looking for the Z-axis to move in a continuous motion from the face of the part towards the chuck or from the face of the chuck towards the end of the part. You cannot change direction in the Z-axis with out defining the tool path as a type II canned cycle. If this is the case you need to add a X-axis reference on the same line as the first Z-axis move after the G71.