CI853 (MODBUS RTU)

S800 I/O is a comprehensive, distributed and modular process I/O system that communicates with parent controllers and PLCs over industry-standard field buses. Thanks to its broad connectivity it fits a wide range of process controllers and PLCs from ABB and others.

Features and benefits

  • MODBUS RTU is a standard protocol widely spread because of its ease of use and reliability. Modbus RTU is an open, serial (RS-232 or RS-485) protocol derived from the Master/Slave architecture exchanging information in half duplex mode. The Modbus functionality can be configured both on the COM ports of AC 800M and CI853.
  • Siemens 3964R can be used on the build in COM3 port and optionally on the CI853 ports. A standard RS-232C/485 communication channel is required.
  • Self-defined Serial Communication can be used on the built in COM3 port (on an AC 800M Controller) and optionally on the CI853 ports. The CI853 also supports Hot Swap.