Chapter 4 Human Machine Interface
© National Instruments Corporation 4-17 BridgeVIEW User Manual
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