Siemens SIMATIC S7-1200 CM 1241 RS485 Communication Module 6ES72411AH320XB0

The Siemens CM 1241 communication module adds an RS485 interface to SIMATIC S7-1200 PLCs, enabling serial communication with devices using USS or Modbus RTU protocols. It supports data rates from 9.6 to 115.2 kbit/s and provides electrical isolation between the interface and backplane bus.

Advantages

This module expands the connectivity of your S7-1200 system, allowing integration with drives, instruments, and other serial devices. Its galvanic isolation enhances noise immunity in industrial environments. Configuration is straightforward via TIA Portal, and firmware updates are possible.

Suitable for

• Connecting Modbus RTU slave devices to S7-1200 PLCs
• Controlling USS protocol drives (e.g., SINAMICS)
• Point-to-point serial communication with third-party equipment
• Applications requiring isolated RS485 communication

Key specifications

• Interface: RS485, 1 port, screw terminals
• Protocols: USS, Modbus RTU master/slave
• Data transfer rate: 9.6 to 115.2 kbit/s
• Supply: 24V DC via backplane bus, max 50 mA
• Electrical isolation: Yes
• Mounting: DIN rail
• Operating temperature: -20 to +60 °C
• Degree of protection: IP20

Recommendations

For reliable serial communication in automation projects, the CM 1241 is a proven choice. Ensure proper grounding and use shielded twisted-pair cable for RS485 networks.