What is the method used for sampling point values called?

The method used for sampling point values is called Change-of-Value (COV). This technique is integral in monitoring and responding to changes in a system's state or outputs. COV works by specifically detecting and sampling data when there is a significant change in the parameter of interest. This allows for efficient data management by reducing the amount of data that is continuously logged and focusing only on relevant changes.

In many monitoring systems, COV methodologies are used to trigger actions or notifications when certain thresholds are crossed, providing timely responses to changes without having to analyze continuous streams of data. This is particularly valuable in applications where real-time data is critical, as it enables more responsive and efficient system operations.

Other options, while related to data and monitoring, do not specifically define the process of sampling point values in the same manner. For instance, data logging refers to the continuous recording of data over time, signal processing pertains to the manipulation or analysis of signals for interpretation, and point evaluation involves assessing specific values without the emphasis on detecting changes. Thus, COV is the most accurate method described for the process of sampling point values based on changes.