Mitsubishi Electric CR750-Q Instruction Manual page 53

3Explanation of operation methods
CAUTION
If any posture components (A, B and C) become 180 degrees as a result of align-
ing the hand, the component values can be either +180 degrees or -180 degrees
even if the posture is the same. This is due to internal operation errors, and there
is no consistency in which sign is employed. If the position is used as position data
for the pallet definition instruction (Def Plt) and the same posture component val-
ues include both +180 degrees and -180 degrees, the hand will rotate and move in
unexpected ways because the pallet operation calculates positions by dividing the
distance between -180 degrees and +180 degrees. When using position data
whose posture component values include 180 degrees for pallet definitions, use
either + or - consistently for the sign of 180 degrees. Note that if the position data
is used directly as the target position in an interpolation instruction, the hand
moves without problem regardless of the sign.
Aligning the Hand 3-33