The real application of industrial robots is on production lines (such as automobile assembly lines, semiconductor silicon wafer handling, etc.). After the robot's various handling motion trajectories are debugged, it also needs to cooperate with the action requirements of the production line, which means it also needs to connect and communicate with the PLC. The two exchange signals, and the PLC tells the robot when to carry out the work and the robot notifies the PLC when it completes the work. Through such interactive communication, the robot can act as a "member" of the entire production line and complete the entire production task with other mechanisms on the production line.
I. Communication Connection between Industrial Robot and PLC
If we master both industrial robot programming and PLC control technology, then controlling the robot via PLC becomes very simple. It simply requires effectively connecting the industrial robot and the PLC and transmitting signals between them.
There are two types of communication between industrial robots and PLCs: "I/O" connection and communication cable connection. The following describes the control method using the most common method, "I/O" connection, between robots and PLCs.
Figure 1: Composition of PLC and Robot System
The PLC shown in the diagram above is a Siemens brand, with the S7-300 serving as the host computer and the S7-200 connected to the machine tool via I/O signals. The S7-300 and S7-200 are connected via a Profibus bus. The S7-300 is connected to the industrial robot via I/O signals. The industrial robot body and the controller are connected using a built-in communication cable (direct plug-in).
Figure 2: S7-300 (CPU-313) Input/Output Signals
Figure 3: S7-200 input/output signals (controlling the lathe)
Figure 4: S7-200 Input/Output Signals (Controlling the Washing Bed)
