National Instruments BridgeVIEW Tag Configuration

Tag Configuration

This chapter describes tags, the Tag Configuration Editor, how

you edit tags within the BridgeVIEW system, and includes an activity that

illustrates how to use the Tag Configuration Editor. Before you can run a

BridgeVIEW application, you must specify a tag configuration.

A tag is a data value in the BridgeVIEW Engine. Tags can be used to

monitor an I/O point, to store a result of a calculation based on other tags,

or to monitor a tag on another BridgeVIEW Engine. A memory tag is a tag

used for user-specified calculations, and a network tag is a tag remotely

connected to any type of tag on another BridgeVIEW Engine.

This section defines a tag in terms of its attributes and describes how tag

attributes affect Engine operations. You can define and configure tags with

the Tag Configuration Editor, described later in this chapter.

The BridgeVIEW Engine manages the Real-Time Database (RTDB) which

contains information about all the tags in the system. The Engine handles

the following tasks:

• Communicates with device servers or other BridgeVIEW Engines

• Scales tag values

• Tracks alarms and events associated with tags, system errors and

events

• Logs tag values, alarms, events and system messages to disk

You can customize these tasks by configuring each tag with the Tag

Configuration Editor. The Tag Configuration Editor displays five

categories of attributes for each tag: general information, connection,

operations, scaling, and alarms.

Operations, scaling, and alarms attributes describe how the Engine handles

a tag’s data. Each attribute can be further classified by the effect on a

running Engine from changing the attribute.