Rockwell Automation FactoryTalk View Machine Edition Users Guide - Manual (Page 505)

24 • Use embedded variables
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 Local messages—When a display containing a local message display object is open,
and the message the object is showing contains an embedded variable, the value of the
embedded variable is updated whenever a new tag value is read from the data source.
For time and date embedded variables, the time and date are updated as the system
time and date change.
 Information messages—The value of the embedded variable is read when the
information message is first shown. It is not updated after that.
If the message is printed, it is printed using the value the variable had when the
message was first shown. This value is retained if you shut down and restart the
application.
 Alarm messages—The value of the embedded variable is read when the alarm occurs,
and is shown in the message associated with the alarm. It is not updated after that.
If the message is printed, it is printed using the value the variable had when the alarm
first occurred. This value is retained if you shut down and restart the application.
How embedded variables are shown at run time
If there is no valid data available for the embedded variable, the variable is replaced with
question marks (?). This could occur when a display first opens and the data has not
arrived yet, or when there is a problem that prevents communication with the data source.
If a string or numeric embedded variable has been set up but no tag has been assigned, the
embedded variable is replaced with asterisks (*).
Numeric embedded variables
The value shown for a numeric embedded variable depends on whether the tag value is a
floating-point number or an integer. Integer values are shown as is. Floating-point values
are rounded to fit the specified number of digits for the variable.
For example, if the variable is set up to show 6 digits, 1234.56 is rounded to 1234.6.
1234.44 is rounded to 1234.4. The decimal counts as one of the digits.
For more information about how values are rounded, see page 7-2.
If the tag value, including the decimal point and minus sign, contains more digits than
specified for the variable, the numeric variable is replaced with asterisks.
For example, if the variable is set up to show 6 digits, and the tag value is -123456, the
variable will be replaced with asterisks.
Literal numbers are shown using the same rules as numeric tag values.