National Instruments BridgeVIEW 用户手册

Chapter 4

Human Machine Interface

© National Instruments Corporation

4-17

Tag Data Type

BridgeVIEW has a special data type called the tag data type that is aware 
of the available tag names and tag group names contained in the current 

.scf

 file. All BridgeVIEW functions that can operate on tags or tag groups 

use the tag data type. The tag data type is marked with a valve glyph. 
Constants and wires in the block diagram carrying this tag information 
are displayed in purple.

The tag control and indicator can be found in the Controls»Strings palette. 
The tag constant can be found in the Functions»Tags palette. The 
Functions»Tags palette also contains functions that convert between a tag 
data type and a string data type, and a special “not a tag” constant. The 
following illustration shows the tag control, indicator and constant as they 
appear on the front panel and block diagram.

Tag controls, indicators and constants also can be contained in arrays. 
Many BridgeVIEW VIs operate on arrays of tags.

When you drop a tag control, indicator, or constant on a front panel, you 
can click on the right menu ring button of the tag control to display a list of 
the available tags and tag groups and select one. 

Tag groups are distinguished from individual tags in the list by a folder 
glyph. A special group 

<ALL>

 also appears in the list. This is a default 

group that contains all the tags in your 

.scf

 file. The following illustration 

shows a list of tags and tag groups.

Front Panel View of Tag Controls and Indicators

Block Diagram View of a Tag Control and Incidator, and Tag Constant