The picture demonstrates the typical Cartesian coordinate system layout for the SCARA. Based on the position of arm1 and arm2, the SCARA Main CPU converts their radian coordinates to rectangular for the above coordinate system.
If an area within the above work envelope is an area that the robot is unable to travel to, the parameters can be altered to allow for a work envelope "danger zone".
The parameters to change to limit the amount of SCARA travel is called the "Software Limit" or "Soft Limit". There is a "Soft Lim+" and "Soft Lim-". Soft Lim- for the SCARA arms 1 and 2 is always 0. By increasing the Soft Lim- or decreasing the Soft Lim+, the work envelope can be changed to fit your system's needs.`