About state summary replication

State summary replication summarizes the states of a tag value. State summary replication can be applied to analog (integer only), discrete, and string tags.

You use this for analyzing process variables with a limited number of states, such as a machine’s state of running/starting/stopping/off. State summary replication provides the following, for each distinct state:

• Total time

• Percent of the cycle

• Shortest time

• Longest time

• Average time

• OPC Quality

• Value

A state summary results in a series of values, each representing a different state, for the same tag and time period.

When you retrieve the data, you specify which calculation you want to return. For more information, see Querying the StateSummaryHistory view in the AVEVA Historian Retrieval Guide.

The functionality provided by analog summary replication is similar to using the ValueState and RoundTrip retrieval modes.

You can define state summary replication for a large number of states, but state data is dropped if the number of states occurring in the same reporting period exceeds the maximum number of states allowed. You configure the maximum states when you create the state summary tag. The default number of maximum states is 10. The Replication subsystem will calculate summaries for the first 10 distinct states, in the order in which they occur in the data (not in numeric or alphabetic order). Be aware that the higher the number of maximum states, the more system resources are used to keep track of the time-in-state for each distinct state.