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Echelon OpenLNS User Manual

Page 514

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OpenLNS Programmer's Reference

477

clients.

Syntax

parentObject = object.Parent

Element

Description

parentObject

The object that is the parent of the

specified object.

object

Any object for which the parent is

desired.

Data Type

Object.

Read/Write

Read only.

Added to API

Depends on the object used to access the property. Generally,

this property exists for an object as soon as the object is

added to the API.

Tag

Summary

Stores any extra data associated with the monitor point or

monitor set.
The data stored in this property is not used by OpenLNS, and

is available as soon as the data point or monitor set is created

in a monitor and control session. You can use this property to

store any data your application may need when using the

monitor set or monitor point. For example, you could store

the name of the monitor set that a message or network

variable monitor point belongs to, or the name of the

application device that a monitor set belongs to.
The Tag properties for all NvMonitorPoint and

MsgMonitorPoint 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