National Instruments BridgeVIEW - Manual (Page 28)

Chapter 1 Introduction
© National Instruments Corporation 1-5 BridgeVIEW User Manual
• Attribute Nodes— Attribute nodes are special block diagram nodes that
you can use to control the appearance and functional characteristics of
controls and indicators. For more information about attribute nodes,
refer to Chapter 13,
Front Panel Object Attributes .
• Arrays, Clusters and Graphs—An array is a resizable collection of
data elements of the same type. A cluster is a statically sized collection
of data elements of the same or different types. Graphs commonly are
used to display data. For more information about arrays, clusters, and
graphs, refer to Chapter 14,
Arrays, Clusters, and Graphs .
• VI Server—The VI Server allows you to control when a VI is loaded
into memory, run, and unloaded from memory. For more information
about VI Control VIs, refer to Chapter 15,
Application Control .
Tag Configuration
A tag value is acquired and/or controlled by a device server that
communicates with the BridgeVIEW Engine and can be read or set by
a VI in your HMI application. Tags can be of the following types: input,
output, Input/Output, or memory. You can configure tags through the
Tag Configuration Editor. A tag configuration consists of its data type,
connection, scaling, operations, and alarms settings. For more information
about this topic, refer to Chapter 3,
Tag Configuration .
Data Type
A tag data type can be analog, discrete, bit array, or string. Analog tags
have continuous values with a specified range (such as 0.0 to 100.0).
Discrete tags have values that are either ON (1) or OFF (0). Bit array tags
are comprised of up to 32 bits, each of which can have an ON (1) or OFF (0)
state. String tags consist of ASCII characters or binary data and can be of
any length.
General
General includes the following tag attributes:
• Tag name
• Tag description
• Tag group
• Length (for bit array and string tags)