The ABB RLM01 is a Redundant Link Module designed to enhance the reliability and availability of industrial automation systems. As a key component of ABB’s AC 800M controller series, the RLM01 is used in conjunction with two CI854A Profibus-DPV1 communication interface modules to establish a fully redundant communication link. This setup ensures that if one communication line fails, the system seamlessly switches to the backup line, preventing costly downtime and maintaining continuous process control. The RLM01 is essential for critical applications where system integrity and uninterrupted operation are paramount, providing a robust solution for high-availability Profibus networks.