Chapter 4
Human Machine Interface
4-2
©
National Instruments Corporation
There are several general G programming principles with which you should
be familiar before you build an HMI. These principles are listed below:
•
Building basic G front panels and diagrams
•
Using controls and indicators
•
Using the tag data type
•
Using the basic principles of dataflow programming
•
Using basic programming constructs such as the Sequence structure
and While Loop
•
Using the Time and Dialog VI library
To learn about any of the topics above, see the
G Tutorial
section of this
manual and complete the activities. For more detailed information, see the
G Programming Reference Manual.
For more advanced HMI programming, you also should know how to use
the G control and indicator attribute nodes and the VI Server functions.
For more information about this topic, see Chapter 13,
.
You might want to divide your HMI into several panels so the operator can
navigate through them using buttons on the screen. The Panel G Wizard
helps you generate the navigation system by automatically generating code
and attaching it to front panel buttons. For more information about the
Panel G Wizard, see Chapter 7,
.
How Do You Build an HMI?
To build an HMI, use the graphical controls and indicators to lay out the
user interface objects on the front panel, and a special set of VI libraries
on the block diagram to do the following:
•
Read and write tag values
•
View and acknowledge alarm states and events
•
Display historical and real-time data
•
Read tag configuration and security information
•
Control the BridgeVIEW system programmatically
•
Access and change tag attributes
•
Control output tags
