Rockwell Automation FactoryTalk Historian SE 3.0 Live Data Interface User Guide - Manual (Page 31)

5
●
Point Configuration
●
●
●
●
●
25
available in the Common Files > Rockwell > Help folder in your Program
Files directory.
Exception Reporting
For each data point, you can set the following three attributes to configure
its exception reporting specification:
Exception
Deviation
(ExcDev):
Specifies in engineering units how much a point's value must change
before the interface considers it as a significant value, and sends it to
the server. As a general rule, you should set the exception slightly
smaller than the precision of the instrument system.
Exception
Minimum (ExcMin): Specifies a limit on how frequently the interface can report values to
the server. For example, if you want the interface to wait full ten
minutes before reporting a new value to the server, then you would
set the ExcMin attribute to ten minutes. ExcMin is typically set to zero.
Exception
Maximum
(ExcMax):
Specifies a limit on how long the interface can go without reporting a
value to the Historian server. After the ExcMax time period, the
interface sends the next new value to the server, regardless of
whether the new value is different from the last reported value.
For information on exception reporting, refer to "Exception Reporting and
Compression Testing" in the FactoryTalk Historian SE Server Reference Guide ,
available from Start > Programs > Rockwell Software > FactoryTalk
Historian SE > Help.
Output Points
Output points control the flow of data from the Historian Server to any
destination that is external to the server, such as the FTLD server. The
FTLD Interface uses Location3=2 to indicate an output point.
Outputs are triggered for UniInt-based interfaces. That is, outputs are not
scheduled to occur on a periodic basis. There are two mechanisms for
triggering an output, as described in the sections that follow.