Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 763)

L-force | PLC Designer
PLC Designer Visualization

DMS 3.2 EN 02/2011 TD29 761
The Placeholder button leads to the 'Replace placeholder' dialog. It lists in the
'Placeholder' column all the placeholders which had been inserted in the configuration
dialogs of the "mother"-visualization and offers in the 'Replacements' column the
possibility of replacing these for the current reference with a definite value. Which
replacements are possible in a given case depends on whether a value group was
predefined in the 'Extras' 'Placeholder list' dialog in the "mother"-visualization. If this
is the case, it will be displayed in a combo box for selection. If nothing was pre-
defined, double clicking on the corresponding field in the Replacements column opens
an editing field which can be filled in as desired.
A further possibility for replacing placeholders in references occurs directly when you
define the call of a visualization by an entry into the Zoom to vis. option field in the
configuration dialog ('Input' category).
Note!
No control of the chronological sequence of replacements is possible! Therefore no
placeholders should be replaced with text that also contains placeholders!
When using placeholders it is no longer possible to check for invalid entries in the
configuration of the visualization element immediately upon compilation of the
project. Hence the appropriate error messages are first issued in Online mode
(...Invalid Watch expression..).
Example of an application of the placeholder concept:
Instances of a function block can easily be displayed with the help of references of the
same visualization. For example, in configuring the visualization visu, which visualizes
the variables of function block, one could begin each variable entry with the
placeholder $FUB$ (e.g. $FUB$.a). If a reference from visu is then used (by inserting
visu in another visualization or by calling via 'Zoom to vis.'), then in the configuration
of this reference the placeholder $FUB$ can then be replaced with the name of the
function block instance to be visualized.
This might look like shown in the following:
In the project define a function block containing the following declarations:
FUNCTION_BLOCK fu
VAR_INPUT
changecol : BOOL; (* should cause a color change in the
visualization *`)
END_VAR