The ABB TC520 System State Collector, part number 3BSE003832R1, is a crucial diagnostic module designed for the ABB Advant Controller 400 series within the System 800xA environment. This unit plays a vital role in maintaining system integrity and reliability by actively collecting status and diagnostic information from the I/O system and the controller itself. The data gathered by the TC520 is essential for fault detection, system monitoring, and preventative maintenance, allowing operators to quickly identify and resolve issues, thereby minimizing downtime and enhancing operational efficiency. Its seamless integration with the Advant OCS (Open Control System) makes it an indispensable component for complex industrial automation applications.