Common Data Tag

Introduction

A Data Point Tag stores a single data value with an associated quality and timestamp.

These data point tags are supported:

Icon Tag Type Version Description
Analog tag Analog Data Tag 1.0 A floating point value.
Digital tag Digital Data Tag 1.0 A single bit or boolean value.
Double word tag Double Word Data Tag 1.3 A 32-bit word value.
String tag String Data Tag 1.2 A string value.
Word Data Tag Word Data Tag 1.2 A 16-bit integer value.

Configuration Properties

The Data Point Tag supports the configuration properties of the Core Tag plus these properties:

Property Type Version Description
AllowForce BOOL 3.21 Whether the user can force the tag's value to a fixed constant value.

Dynamic Properties

The Data Point Tag supports these dynamic properties:

Property Type Description
Quality INT The quality of the current value
Timestamp DATE_AND_TIME The timestamp of the last update to this tag
DataSource WSTRING A string describing where the tag data originates from.
IODataSource WSTRING A string describing where the tag data originates from.
DisplayValue WSTRING The display value of the tag.
DisplayColor DWORD The display color of the tag.
HistoricDataTable STRING The name of the database table used to store historic values for this tag.

Relationships to Other Tag Types

The Data Point Tag builds on the features of these tag types:

The Data Point Tag is used as a building block for these tag types:

Further Information

Glossary

For the meaning of terms used in Fernhill SCADA.