Echelon OpenLNS - Manual (Page 690)

OpenLNS Programmer's Reference 653
application device that a monitor set belongs to.
The Tag properties for all NvMonitorPoint objects in
permanent monitor sets are cached when the monitor set is
opened. As a result, any changes made the Tag properties of
these monitor points while the permanent monitor set is open
will not be accessible until the monitor set is closed and
re-opened. When initially created, monitor points and
monitor sets will have a null Tag value. However, if you add
a monitor point to an open monitor set and set its Tag value
in the same transaction, you will be able to access the Tag
value during that monitor and control session, as all data
would be written to the device as soon as the transaction is
committed. You should note that this behavior does not apply
to monitor points in temporary monitor sets. Temporary
monitor sets support "live" updates to the value of the Tag
property.
A well-defined monitoring application will include any
information necessary to quickly and efficiently identify the
monitor point in this property. This will eliminate the need to
gather such information from the database, or to perform
other time-consuming activities, during the monitoring
process.
Availability Local, full, lightweight, and independent clients. Note that
temporary MonitorSet objects are not available on
Independent clients.
Syntax tagValue = Object.Tag
Element Description
Object The monitor point or monitor set
object to be acted on.
tagValue The tag associated with the object.
Data Type Variant .
Read/Write Read/write.
Added to API LNS Release 3.0.
Events
The NvMonitorPoint object contains the following events :
• UpdateErrorEvent
• UpdateEvent