Rockwell Automation FactoryTalk Historian SE 3.0 UniInt Interface User Guide - Manual (Page 22)

Historian Point Configuration
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user‘s manual for detailed discriptions of the Historian Point Attributes that are relavant to
the interface.
The following section describes common point attributes. The second and third sections
describe how input and output points are configured and used.
Point Attributes
The following Historian Point Attributes are used by UniInt based interfaces. Refer to the
interface documentation to determine whether the standard UniInt implementation for a
particular attribute is applicable. Some attributes may have additional or different meanings
for individual interfaces. If the specific attribute is not mentioned by the interface
documentation of a UniInt based interface, then the attribute will affect the data in
accordance with the explanation in this manual. Also, most UniInt based interfaces use a
number of attributes that are not described here.
Tag
The words point and tag are frequently used interchangeably, but there is a difference. A tag
is a label or name for a point. Any tag name can be used in accordance with the normal
Historian point naming conventions.
PointSource
The PointSource is a unique, single or multi-character string that is used to identify the
Historian point as a point that belongs to a particular interface. For example, a single point
source using the letter R may be chosen to identify points that belong to the Random
interface. In order to implement this, the PointSource attribute should be set to R for every
Historian Point that is configured for the Random interface. Then, if /ps=R is specified on
the startup-command-line of the Random interface, the Random interface will search the
Historian Point Database for every Historian point that is configured with a PointSource of
R. Likewise, a multi-character PointSource using the string Boiler1 may be used to
identify points that belong to the PIIFC Interface. To implement this, the PointSource
attribute would be set to Boiler1 for every Historian Point that is configured for the PIIFC
Interface. Then, if /ps=Boiler1 is used on the startup command-line of the PIIFC
Interface, the Interface will search the Historian Point Database for every Historian point that
is configured with a PointSource of Boiler1
. Before an interface loads a point, the
interface usually performs further checks by examining additional Historian Point Attributes
to determine whether a particular point is valid for the interface. For additional information,
see the /ps parameter.
The following table explains length limits imposed on the PointSource for different
configurations. When the maximum possible lengths differ for the software installed on site,
the shortest length applies.
PI API Historian Server PI SDK Maximum Length
1.6 or higher 2.x or higher na 100