Which of the following are not valid retrieval modes?

The retrieval modes in $AVEVA Historian are designed for different purposes, and understanding which terms are officially recognized is important for effective data management. In this context, the retrieval mode referred to as "StdDev" is not a valid retrieval mode in $AVEVA Historian.

The valid retrieval modes typically include "NumCount," which provides a count of numeric values, and "Range," which is used to specify a time range for data retrieval. Additionally, "Event" serves to retrieve data based on specific trigger events. Each of these retrieval modes serves distinct analytical needs, allowing users to manipulate and extract data efficiently according to their specific requirements.

By identifying "StdDev" as an invalid mode, it emphasizes the importance of familiarizing oneself with the correct terminology and functions within the software to avoid errors during data retrieval processes. Understanding these distinctions helps users in effectively leveraging the capabilities of the $AVEVA Historian for their data analytics needs.