26.3.1 PLC Interface To a Robot

Problem: A robot will be loading parts into a box until the box reaches a prescribed weight. A PLC will feed parts into a pickup fixture when it is empty. The PLC will tell the robot when to pick up a part and load it into the box by passing it an ASCII string, "pickup".


Figure 26.1 Box Loading System

Solution: The following ladder logic will implement part of the control system for the system in Figure 26.1 Box Loading System.


Figure 26.1 A Box Loading System