Yes, the Siemens S7-1200 PLC fully supports Modbus TCP communication. This allows it to connect and exchange data with a wide range of industrial devices such as HMIs, SCADA systems, and other PLCs over a standard Ethernet network. The best part is that it doesn’t need any extra hardware — everything works through the S7-1200’s built-in PROFINET (Ethernet) port. Inside the TIA Portal software, you can use the predefined MB_SERVER and MB_CLIENT function blocks to set up the PLC as either a Modbus TCP server or a client, depending on your application.
When the S7-1200 acts as a Modbus TCP server, it responds to data requests from other Modbus devices, sharing inputs, outputs, or data blocks. As a client, it can actively send commands and read data from other Modbus servers. The communication happens through defined memory areas or data blocks (like MB_DB), which represent Modbus registers and coils. This setup provides a reliable and flexible way to integrate the S7-1200 with non-Siemens systems while maintaining fast Ethernet performance. In short, the Siemens S7-1200 supports Modbus TCP seamlessly, making it a powerful controller for modern automation networks that combine multiple brands and protocols.