B&B Electronics VFG3000 - Manual - Manual (Page 93)

C ONFIGURING D ATA T AGS M ORE THAN T WO A LARMS
R EVISION 1 P AGE 77
The parentheses, the space and the dash will all be included when the field is
displayed, but only the 10 digits indicated by the ‘0’ characters will be stored in the
string. Similarly, if data entry is enabled for a field using this template, the cursor
will skip the various non-numeric positions when moving left or right, and will only
allow numeric characters to be entered for those positions that can be selected.
• The Length property is used in lieu of the template to indicate how many
characters should be reserved on a page when displaying this string. If a string
variable is marked as retentive, it makes sense for this property to be equal to the
length entered on the Data tab, but this is not obligatory, as you may want to
allocate more or less space on the display for layout purposes.
• The Justification property is used when a template is not specified, and indicates
how strings shorter than the Length property should be positioned within the
storage allocated for the string. It is distinct from the Justification property of the
display format, in that it impacts the data that is actually stored.
T
HE
C
OLORS
T
AB
The Colors tab of a string tag contains the following properties…
The tab is used to specify the default colors to be used to display this tag.
M
ORE THAN
T
WO
A
LARMS
If your application requires more than two alarms (or indeed triggers) for a tag, define a
formula to be equal in value to the primary tag, and set the extra alarms on the alias. For
example, if you have a variable called
Level which is mapped to N7:100 in a PLC, and you
need to create a third alarm for that tag, create a variable called, say, LevelAlias and set its
value property to Level . You can then set additional alarms on this alias tag.
V
ALIDATING
T
AGS
Selecting the Tags icon in the left-hand pane of the Tags window will allow access to the
Validate All Tags button. Pressing this button will recompile all expressions in your database,
fixing any broken communications references and updating tag reference counts. You should