Trend log data is best described as which of the following?

Trend log data is best described as which of the following?

• A. A historical record of sensor and setpoint values used for diagnostics, performance verification, and troubleshooting
• B. A real-time dashboard of current values
• C. A log of equipment warranty dates
• D. A list of occupant preferences

Answer: (A)

Trend log data provide a historical sequence of sensor readings and setpoint values collected over time, which makes it possible to analyze how the system behaved under different conditions. This kind of data is used for diagnostics, performance verification, and troubleshooting because you can see patterns, verify that control logic worked as intended, and spot anomalies or drift after the fact. It’s not simply a real-time snapshot of current values, nor is it about warranty dates or occupant preferences. For example, you can review trend logs to see if a cooling cycle aligns with the setpoint, detect sensor drift by comparing actual versus commanded temperatures over days, or verify that energy use matches expected performance after a retrofit.

Trend log data provide a historical sequence of sensor readings and setpoint values collected over time, which makes it possible to analyze how the system behaved under different conditions. This kind of data is used for diagnostics, performance verification, and troubleshooting because you can see patterns, verify that control logic worked as intended, and spot anomalies or drift after the fact. It’s not simply a real-time snapshot of current values, nor is it about warranty dates or occupant preferences. For example, you can review trend logs to see if a cooling cycle aligns with the setpoint, detect sensor drift by comparing actual versus commanded temperatures over days, or verify that energy use matches expected performance after a retrofit.