Rockwell Automation FactoryTalk Historian SE 3.0 UniInt Interface User Guide - Manual (Page 54)

Interface Health Points
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Scan Class Scan Time
ExDesc Keyword: [UI_SCINSCANTIME]
Update Interval: At the completion of associated scan class.
Description:
The Scan Class Scan Time is the total amount of elapsed time in milliseconds to read data
from the foreign device, populate the input tags, and then send the data to Historian. The
value for this tag is updated after each completed scan.
Scan Class Input Device Scan Time
ExDesc Keyword: [UI_SCINDEVSCANTIME]
Update Interval: At the completion of associated scan class.
Description:
The Scan Class Device Scan Time is the time in milliseconds to read data from the foreign
device and populate the input tags. The Scan Class Device Scan Time is a subset of the total
Scan Class Scan Time and can be used to determine the percentage of time spent
communicating to the foreign system compared with the percentage of time spent
communicating with Historian.
If the Scan Class Skipped tag value is increasing, the Scan Time tags along with the Device
Scan Time tags can be used to help identify where the delay is occurring – the foreign system
communication, the FactoryTalk Historian System communication, or elsewhere in the
interface controlloop.