Flow Ctrl Tech Engineering

Modbus RTU vs Modbus TCP: Complete Protocol Architecture & Framing Comparison

Detailed engineering comparison of Modbus RTU and Modbus TCP: frame structure, CRC16 vs MBAP header, physical media, timing constraints, and field conversion.

  • Modbus RTU uses strict time-based delimiters (t3.5 silence) and CRC-16 mathematical error checking.
  • Modbus TCP replaces the CRC and slave address with a 7-byte MBAP header running over standard TCP/IP port 502.
  • Modbus RTU is limited to single-master query-response on RS-485, while Modbus TCP supports concurrent multiple clients.

Flow Ctrl Tech Engineering: Turnkey industrial automation, PLC programming, SCADA development, HMI, fieldbuses, and IIoT architectures. Contact our engineering center at [email protected] or phone +91 91110 91005.