Bridge User Manual

BridgeVIEW Environment

This chapter describes the BridgeVIEW environment. It explains

thebasicconcepts behind G, the programming language upon which

BridgeVIEW isbuilt, the BridgeVIEW Engine Manager, system errors

andevents, the Tag Monitor utility, and the Tag Browser utility. This

chapter also explains how to access online help for BridgeVIEW and

provides an activity that illustrates how to examine the front panel

andblock diagram of a virtual instrument (VI).

What Is G?

G is a programming language, much like various commercial C or BASIC

development languages. However, G is different from those applications

inone important respect. Other programming languages are text-based

languages that create lines of code, while G is a graphical programming

language that creates programs in block diagram form.

You can use G with little programming experience. G engineers and

programmers rely on graphical symbols and data flow rather than textual

language to describe programming actions. Data flow is a programming

system in which nodes execute when they have received all required input

data, and produce output automatically when they have executed.

G has extensive libraries of functions and subroutines for most

programming tasks. BridgeVIEW includes conventional program

development tools for G, so you can set breakpoints, animate program

execution to see how data passes through the program, and single-step

through the diagram to make debugging and program development easier.

How Does G Work?

G includes libraries of functions and development tools designed

specifically for HMI development, data acquisition, and instrument

control. G programs are called virtual instruments (VIs) because their

appearance and operation imitate actual instruments. However, they are

analogous to functions in conventional programming languages.