Write, Properties, Write m – Echelon OpenLNS User Manual

Page 272: Writ

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OpenLNS Programmer's Reference

235

Syntax

dpObject.Read

Element

Description

dpObject

The

DataPoint

object being acted upon.

Added to API

LNS Release 3. 0.

Write

Summary

Updates the value of the source object controlled by this data

point to match the current value stored in the data point’s

Value, RawValue, and FormattedValue

properties.

Writing to either of the Value, RawValue, and

FormattedValue properties updates the values of all three so

that they always match. However, you must call the Write

method to propagate these new values to the source object.

After the Write method is called, OpenLNS will update the

value of the data point’s source object to match the value of

these properties.
For example, if the data point was obtained through a

network variable, the value of the network variable on the

physical device on the network would be updated to match

the values of these properties after the Write method was

called. This ensures that the data point returns a current

value for its source object.
If the AutoWrite property is set to True, this method will

automatically be called every time the RawValue,

FormattedValue, or Value properties are written to.
Note:

If you call this method on a

DataPoint

obtained from a

NetworkVariable

or

NvMonitorPoint

object before reading its

value from the network (either explicitly by calling the

Read

method, or implicitly when the

AutoRead

property is set to

True), or before setting the Data Point’s value with the

RawValue

,

FormattedValue

or

Value

properties, the DS,

#370 lcaErrLnsDsInvalidArg exception will be thrown.

This indicates that the

DataPoint

’s buffer is empty.

Availability

Local, full, lightweight, and independent clients. Note that

some objects containing this property are not available to

Independent clients.

Syntax

dpObject.

Write

Element

Description

dpObject

The

DataPoint

object being acted upon.

Added to API

LNS Release 3.20.

Properties

The DataPoint

object contains the following properties

:

AutoRead

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