About Summary Replication

Summary replication takes information from a source tag on a lower-tier historian and summarizes the tag data to a next-tier historian in one of two types of summary tag:

• Analog summary tag

• State summary tag

If a lower-tier historian is unable to perform a scheduled summary calculation for any reason, it adds a record about the event into a replication queue. When there are enough system resources available, or there is a specific event from another subsystem, the lower-tier historian can perform the summary calculations and clear the queue.

You can add analog or state summary tags one at a time or in multiples.

State summary replication is not supported for scaled tags.