What is the primary function of a data recorder in a process control system?

• A. To adjust valve positions
• B. To compute process setpoints
• C. Records process data over time
• D. To generate control signals for actuators

Answer: (C)

The main idea is to capture and store measurements from the process so you have a history of how the variables behaved over time. A data recorder logs values like temperature, pressure, flow, or level at regular intervals and keeps them for later review and analysis. This historical record supports trend analysis, performance monitoring, and compliance reporting, and it helps with troubleshooting by showing how the process changed during a period. It doesn’t touch or control the process—there are separate devices that adjust valve positions, compute setpoints, or generate control signals for actuators. The data recorder’s value is in providing an accurate, time-stamped record of how the process behaved.