The CM 1241 Communication Module (6ES7 241-1CH32-0XB0) enables robust RS-422/RS-485 serial communication for SIMATIC S7-1200 PLC systems. It features a secure 9-pin D-Sub female connector and supports versatile industrial protocols including Freeport, Modbus RTU (master/slave), ASCII (via library), 3964(R), and USS (via library), enabling seamless integration with various serial devices and legacy systems.
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Totally Integrated Automation

Technical Specifications
Specification Description
Interfaces One RS-422 or RS-485 channel via 9-pin D-Sub female connector
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Supported Protocols Freeport, ASCII, 3964(R), Modbus RTU Master & Slave, USS
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Totally Integrated Automation

Supply Voltage 24 V DC (range: 20.4 – 28.8 V) from the S7-1200 backplane
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Industry Mall

Power Consumption Typical power dissipation: 1.1 W; draws approx. 220 mA from 5 V backplane bus
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Totally Integrated Automation

Isolation 707 V DC (type-tested) between RS-485 signals, chassis, and CPU logic common
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Transmission Specs Max cable length: up to 1,000 m (depending on baud rate)
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Totally Integrated Automation

Baud Rates 300 to 115.2 kbit/s (includes standard rates like 9.6 kbit/s, 19.2 kbit/s, etc.)
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Parity Options No parity (default), even, odd, mark, space; Stop bits: 1 (default) or 2
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Diagnostics LED indication and built-in diagnostics for status monitoring
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Environmental Specs Ambient operation: –20 °C to +60 °C; Storage: –40 °C to +70 °C; Humidity up to 95% (non-condensing)
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Protection Rating IP20 (standard for S7-1200 modules)
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Totally Integrated Automation

Certifications CE, CSA, UL/cULus, FM, RCM, KC, Marine approvals
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Mechanical Dimensions Width: 30 mm; Height: 100 mm; Depth: 75 mm; Weight: Approx. 155 g
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Franklin Empire
Engineering Highlights

Comprehensive Protocol Support: Supports a wide range of serial communication standards—Freeport, Modbus RTU (both roles), ASCII, 3964(R), and USS—ideal for connecting to diverse field devices and legacy systems.

Long-Distance Communication: Capable of communication over up to 1,000 m, depending on baud rate, making it suitable for extended field wiring applications.

High Electrical Isolation: 707 V DC isolation ensures enhanced protection against transient voltages and fault conditions.

On-Module Diagnostics: LED status indicators provide real-time feedback for quick troubleshooting and monitoring.

Industrial-Grade Design: Built to withstand demanding operating conditions, including wide temperature ranges and certified for various industrial standards.

Key Applications

Adding serial communication, especially RS-422/RS-485, to S7-1200 installations.

Integrating with devices using legacy protocols such as Modbus RTU, USS, or Freeport.

Extending machine networks across long cable distances in industrial environments.

Upgrading automation systems without the need for custom converters or adapters.

Summary

The SIMATIC CM 1241 RS-422/485 Communication Module (6ES7 241-1CH32-0XB0) enriches S7-1200 PLC systems with reliable, high-performance serial connectivity. Engineered for flexibility, durability, and seamless integration, this module is a solid choice for expanding industrial automation capabilities, especially when legacy or long-distance serial communication is required.