Rockwell Automation 1756-HIST2G FactoryTalk Historian ME 2.2 - Manual (Page 91)

5 • M ANAGING P OINTS
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The name must be unique.
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The first character must be alphanumeric or the percent sign (%).
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No control characters (such as linefeeds or tabs) are allowed.
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The following characters are not allowed: * ' ? ; { } [ ] | \ ` ` " ( )
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Descriptor - defines the base point attribute that can be used to provide a textual
description of a point. The Descriptor is a common attribute to display in various
client applications and user reports.
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Extended Description - only used with Trigger Input or Output tags. Use this field
to specify:
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EVENT = <tag name> <condition>
where <condition> is Increment, Decrement, Nonzero, Any, or Anychange
Or
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TRIG = <tag name>
If you enter a tag name in this field, the source tag being referenced must not be
high speed or have a scan rate of faster than 1 second. Otherwise, the module will
generate an error and will not allow you to save your work in the Point Property
page.
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Instrument Tag - indicates the controller from which the data is coming. If you
replace a controller with a different one that measures the same process value, it is
usually best to continue using the same point. Edit the point as required so that it
will collect the new data.
The format of the instrument tag name is:
[<controllerprojectname>_1_<controllerslotnumber>][<controllertagname>]
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Source Tag - only used with Trigger Input or Output tags. Use this field for the
trigger name. If you enter a tag name in this field, the source tag referenced must
not be high speed or have a scan rate of faster than 1 second. Otherwise, the
module will generate an error and will not allow you to save your work in the
Point Property page.
When defining multiple triggers, make sure that each event calls a different tag
name.
If you want to define a condition in the Extended Description field, you must use
EVENT=triggername. If you use TRIG=triggername, you cannot define a condition
after it.