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