Industry Communication Based on TCP/IP Protocol

The design of control systems needs to ensure communication between multiple PLCs or external IoT devices. Furthermore, there are several ways of communication between them. This article dealt with the PLC communication based on TCP/IP protocol, and compared several communication options between two PLCs of the S7-300 and S7-1200 series connected using Profinet with a solution built in C# connected to the PLC via an OPC server. We used MODBUS TCP, TCON, and PUT/GET program blocks for comparison. We transmitted a digital Boolean data type and an analogue value of the integer data type via Profinet to read data from the S7-300 PLC and send data to the S7-1200. We compared the programming instructions standardly used as a client/server PLC programming with a Windows Forms application, and evaluated the advantages and disadvantages of this solution even when using external IoT devices. The solution was applied and successfully tested for communication between PLC S7-1200 and Nvidia Jetson Nano. We wrote program instructions for PLC in Siemens Tia Portal V15.