Basic Characteristics RAPID

4 Robot Configuration
It is usually possible to attain the same robot tool position and orientation in several
different ways, using different sets of axis angles. We call these different robot
configurations. If, for example, a position is located approximately in the middle of a
work cell, some robots can get to that position from above and from below (see Figure
31). This can also be achieved by turning the front part of the robot upper arm (axis 4)
upside down while rotating axes 5 and 6 to the desired position and orientation (see
Figure 32).
Figure 31 Two different arm configurations used to attain the same position and orientation.
In one of the configurations, the arms point upwards and to attain the other
configuration, axis 1 must be rotated 180 degrees.
axis 4
axis 5
axis 6
Figure 32 Two different wrist configurations used to attain the same position and orientation.
In the configuration in which the front part of the upper arm points upwards (lower),
axis 4 has been rotated 180 degrees, axis 5 through 180 degrees and axis 6 through
180 degrees in order to attain the configuration in which the front part of the upper
arm points downwards (upper).
6-32 RAPID Reference Manual