Rockwell Automation 1756-HIST2G Historian ME 2.1 - Manual (Page 305)

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G LOSSARY
Compression
Specification
The three base attributes that control the compression process
for a particular point: CompDev, CompMax, CompMin.
Although it is technically not included in the specification,
Span affects CompDev, and Compressing determines whether
the specification is needed at all.
Connection Credentials The set of identifying information about a client application
seeking connection to the FactoryTalk Historian ME server.
This information can include the client computer’s IP address
or hostname, the client application’s name, or the Windows
Domain name and Windows user name under which the client
application is running. The FactoryTalk Historian ME server
uses connection credentials to determine if there is a matching
trust.
ControlBus The backplane used by the FactoryTalk Historian ME module
chassis.
Data Type The kind of value that will be used. Both points and point
attributes have a data type. Some of the possible types include
several kinds of numbers, digital, and string.
Deadband A threshold, within the alarm limit, that the rate point must
pass after an alarm is triggered before the point is considered
not to be in alarm.
Digital Point Type A point type typically used when values can only be one of
several discrete states, such as ON/OFF or red/green/yellow.
Event The fundamental unit of information used in the FactoryTalk
Historian ME server. Each event consists of two main
components: a value and a timestamp. The value can be one of
several different data types (such as, string, digital, int32,
float64). The timestamp is always represented as UTC seconds
and can contain a sub-second component.
Event Scheduling A method of triggering program execution when some specific
condition occurs such as the arrival of a new Snapshot event
for a particular point. Event scheduling is one method available
for triggering PE or Advanced Computing Engine (ACE)
calculations.
Term Definition