This interface is composed of methods used to retrieve data, alarms, and
events and their histories from the server.
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ReadData
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This method is used to read the values of one or more data
objects in a list.
Heritage: The method corresponds to the ISO 9506 Manufacturing
Messaging Specification (MMS) Read service.
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ReadEvents
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This method is used to read an event list or a subset of it using
a filter.
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ReadJournalDataAtSpecificTimes
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This method is used to read the historical values at specific
times for one or more data objects within a specific data journal
list. If no entry exists at the specified time in the data journal
for an object, the server creates an interpolated value for that
time and includes it in the response as though it actually existed
in the journal.
Heritage: The set of historical values is referred to collectively
as a "Journal", as described by the ISO 9506 Manufacturing Message
Specification (MMS). This method is derived from the ReadJournal
service defined by that specification.
However, this method only accesses historical data rather than also
accessing historical events as does the MMS ReadJournal service.
This is because the return value of this method is strongly typed to
historical data and not to historical alarms and events.
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ReadJournalDataChanges
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This method is used to read changed historical values that for
one or more data objects within a specific data journal list.
Changed historical values are those that were entered into the
journal and then changed (corrected) by an operator or other user.
Heritage: The set of historical values is referred to collectively
as a "Journal", as described by the ISO 9506 Manufacturing Message
Specification (MMS). This method is derived from the ReadJournal
service defined by that specification.
However, this method only accesses historical data rather than also
accessing historical events as does the MMS ReadJournal service.
This is because the return value of this method is strongly typed to
historical data and not to historical alarms and events.
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ReadJournalDataForTimeInterval
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This method is used to read the historical values that fall
between a start and end time for one or more data objects within a
specific data journal list.
Heritage: The set of historical values is referred to collectively
as a "Journal", as described by the ISO 9506 Manufacturing Message
Specification (MMS). This method is derived from the ReadJournal
service defined by that specification.
However, this method only accesses historical data rather than also
accessing historical events as does the MMS ReadJournal service.
This is because the return value of this method is strongly typed to
historical data and not to historical alarms and events.
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ReadJournalDataProperties
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ReadCalculatedJournalData
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ReadJournalEvents
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This method is used to read a list of historical alarms or
events. This method only accesses historical events rather than also
accessing historical data as does the MMS ReadJournal service. This
is because the return value is strongly typed to historical alarms
and event messages and not to historical data.
To simplify implementation, clients must first define a historical
alarm/event list that the server will prepare to access.
Heritage: The set of historical alarms and events is referred to
collectively as a "Journal", as described by the ISO 9506
Manufacturing Message Specification (MMS). This method is derived
from the ReadJournal service defined by that specification.
However, this method only accesses historical alarms and events
rather than also accessing historical data as does the MMS
ReadJournal service. This is because the return value of this method
is strongly typed to historical alarms and events.
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