Chapter 7 Advanced Application Topics
BridgeVIEW User Manual 7-10 © National Instruments Corporation
When you change programmatic attributes with the Tag Configuration
Editor, you can update Engine processes without shutting down and
restarting the Engine, provided no changes require the Engine to
reconfigure. You can change all operations, alarms, and most scaling, and
raw or engineering range information dynamically.
There are certain attributes you cannot change dynamically. These
attributes require you to edit the .scf file with the Tag Configuration
Editor, and they include tag information like tag name, tag description,
scaling type, engineering unit, data type (analog, discrete, bit array, string),
tag group name, and access rights (input only, output only, Input/Output,
memory); and tag connection information like server, IO Group, and item.
For more information about tag attributes, refer to any one of the five
configuration attributes tables in the section How Do You Configure Tags?
in Chapter 3, Tag Configuration.
Activity 7-2. Use Tag Attributes
Your objective is to use tag attributes to change alarm limits dynamically.
You will use mytanks.scf in the BridgeVIEW\Activity directory, as
edited in Activity 3-1, Configure a Tag, and View the Tag Configuration
Parameters and Tag Values.
1. Open Monitor Product.vi from the BridgeVIEW\Activity
directory. You created this VI in Activity4-3, Read a Tag. If you did
not complete this activity, you can open the VI from the
BridgeVIEW\Activity\Solutions directory.
2. Open the block diagram, select the While loop, and delete it. Because
you released the Wizard Lock in Activity4-3, the HMI G Wizard will
no longer replace the old code, but will generate additional code
instead.
3. Pop up on the tank on the front panel and select HMI G Wizard.
Change the Normal color to Blue, and select the alarms to show for the
HI alarm state only, as shown in the following illustration.