Rockwell Automation FactoryTalk Historian SE 4.0 Live Data Interface User Guide - Manual (Page 25)

Point Configuration Chapter 5
Rockwell Automation Publication HSELD-UM024A-EN-E–September 2013 25
Location2 is not used for the FTLD Interface.
Location3 is used to define a data collection mode:
Item Description
0 - Polled or Event Data is collected based on the scan rate and saved in the buffer.
When the Historian server requests data, the data stored in the
buffer is sent to the server. In this method, the values being sent to
the Historian server are from a buffer, so they may not represent
the exact (current) values in the controllers.
1 - Advise (Default) Data is collected only when a value changes in the controller. It is
not based on the scan rate. It is the default data collection method,
and is the most efficient because data is sent to the Historian server
only when the value changes.
2 - Output Data is written back to the Live Data server such as RSLinx
Enterprise, HMI server such as FactoryTalk View, or OPC server such
as RSLinx Classic. Use this method when you want to write data
points back to the data servers.
Location4 defines the scan class for the Historian point. The scan
class determines the frequency at which input points are scanned for
new values. For more information, see the description of the
/f
parameter in "Command-line Parameters (page 39)".
The updates from the FactoryTalk Live Data server come in groups:
at startup, the interface defines a group on the Live Data server and
adds all points within the given scan class to the group. The
FactoryTalk Live Data server is queried for all points within a group
at the same time; therefore, some consideration should be given to
the creation of scan classes. Having more than one scan class with
the same scan period is allowed, and using different offsets on those
scan classes may improve performance.
Location2
Location3
Location4