WriteValue Tag Command

Introduction

The WriteValue Tag Command writes a new value to a tag.

Parameters

Value : ANY: The new value of the tag.

Remarks

The WriteValue Tag Command writes a new value to a tag. If the tag is derived from an external data source, the write is sent to the data source as a control.

The Value parameter is ANY. ANY is a generic data type, which allows any value. For more information on ANY and other generic data types see Generic Data Types.

The WriteValue Tag Command will attempt to convert the Value parameter to a type compatible with the host tag. The type expected by the driver for each tag type is:

Icon	Tag Type	Expected Value Type
	Analog	LREAL
	Bitmap Image	ARRAY [] OF BYTE
	Digital	BOOL
	Word	UINT
	Double Word	UDINT
	Long Word	ULINT
	String	WSTRING

Note: To avoid errors you should ensure the Value parameter is compatible with the host tag.

You can execute WriteValue Tag Command from:

From an Operator Action using a TagWriteValue Function.
From a Program Tag using a TagWriteValueFB Function Block. See Example Program to learn more.
The Standard Tag Menu when used with one of the tags listed in the Applies To list.
The .NET API. For an example see Executing a Tag Command from .NET Code.
The Java API. For an example see Executing a Tag Command from Java.

To use the WriteValue Tag Command, the user requires the Write User Right.

Requirements

Fernhill SCADA Version	Version 1.0
Required User Right	Write

Applies To

The WriteValue Tag Command can be used with these tag types: