Which component centralizes time-stamped event data from the control loop for trend analysis and reporting?

• A. SCADA
• B. HMI
• C. Data Historian
• D. Ladder Logic

Answer: (C)

A Data Historian is designed to centralize time-stamped event data from the control loop for trend analysis and reporting. It collects high-frequency data from PLCs and control systems, stamps each data point with an exact time, and stores it in an efficient, searchable time-series database. This makes it possible to pull up long-term trends, compute statistics, generate reports, and perform analytics across different time periods and variables.

SCADA handles real-time monitoring and data acquisition and may interface with a historian, but its primary role isn’t long-term storage. The Human-Machine Interface provides visualization for operators but does not serve as the centralized repository for historical data. Ladder Logic is the programming language used to implement control logic on PLCs and does not centralize historical event data.