This function block is used to refer to a mask in an HMI, that defines an area serving as background for other objects.

The input bShow is used to show or hide the mask. The background color and a language specific bitmap resource can be set via the inputs lBGClr or iLang and iBmp. The background picture is arranged in a way, that the top left corners of the mask and the bitmap match.

After clicking on the mask or an included element, which does not process user inputs or is disabled, the output bPress will change from LOW to HIGH for one program cycle.

The input idParen and the output idMask are used to change the mask hierarchy. The identification number of the mask that is assigned to the function block is provided at output idMask. If it is connected with the input idParen of a second mask block, the mask of the second function block becomes a child of the mask of the first block. It should be taken into account, that the display area of child masks is limited to the size of the parent mask and that children masks are only displayed when the parents are visible.

The inputs bShow and idParen have no effect on the background window. It is a special mask that is always visible and is used as parent window of all other masks.

HMI mask

The HMI mask is a rectangular area that contains other objects and masks. It is used to create different views for the HMI.


In the parameter dialog the function block is assigned to an HMI mask.

By using the context menu of the function block, the mask designer can be invoked as the parameter dialog. The mask designer is used to create the assignment of the HMI mask. Furthermore the preferences of the HMI mask can be set using the mask designer.

The parameter dialog of the mask can be used to define the default values for the background color and the language and bitmap resource IDs.


Name I/O Type(s) Function
idParent I WORD Parent mask (ID)
iBmp I WORD Bitmap resource (ID)
bShow I BIT Show/hide object
iLang I WORD Language resource (ID)
lBGClr I LONG Background color
idMask O WORD Mask (ID)
bPress O BIT Click signal

Note: If inputs are not connected, the mask appears with the corresponding default parameters that have been entered in the mask designer. Otherwise the input signal from the function block overwrites the according setting in the parameter dialog.


The colored highlight in the function block indicates, whether a HMI mask is assigned or not.