Rockwell Automation FactoryTalk Historian SE 4.0 Live Data Interface User Guide - Manual (Page 12)

Chapter 2 Principles of Operation
12 Rockwell Automation Publication HSELD-UM024A-EN-E–September 2013
At startup, the FTLD Interface tries to establish a connection to
both the FactoryTalk Live Data server and the FactoryTalk
Historian server.
Once the startup is complete, the Interface enters the processing
loop, which includes:
• Servicing scheduled input points. Each Scan Class is processed
in turn.
• Servicing output points as events arrive.
• Servicing triggered input points as events arrive.
The Historian Point Database is checked every 2 minutes for points
that are added, edited, and deleted. When point updates are
detected, the points are loaded (or reloaded) by the Interface as
appropriate. The 2-minute update interval can be adjusted with the
/updateinterval command-line parameter discussed in the UniInt
Interface User Manual.
The manual is located in the UniInt folder ( c:\Program
Files\Rockwell Software\FactoryTalk
Historian\Server\PIPC\Interfaces\UniInt).
The Interface processes a maximum of 25 point updates at a time. If
more than 25 points are added, edited, or deleted at one time, the
Interface will process the first 25 points, wait 30 seconds (or the
length of time specified by the
/updateinterval parameter, whichever
is lower), process the next 25 points, and so on. After all points have
been processed, the Interface will resume checking for updates every
2 minutes (or the length of time specified by the
/updateinterval
parameter).
All tag edits are performed in the following way: old versions of
edited tags are deleted from the interface, new versions are added.
Processing Loops