Connection to specific process variable

Some controls can only access variables of a specific data type, such as VT_DATE or VT_BSTR. Some support access to any data type.

The controls handle the specific data types in a special way. For example, the formatting can be set individually for the data type VT_DATE (date variable). For data type VT_BSTR (text variable), for example, the input limit is applied to the text length. There are also specialised input dialogues for touch operation for these data types.

The "VariableName" property in the "Variable" category in the Properties window is available for linking to the process variable:

VariableName

The full name of a process variable is entered in this property.

You can use the button next to the property to open the Select variable dialogue in which you can select the desired variable.

The following controls can only process specific data types:

Control element	Supported data type	Remark
TextVarIn, TextVarOut	VT_BSTR	Input/output of any text
DateTimeVarIn, DateTimeVarOut	VT_DATE	Input/output of date and time
ColorIndicator, DropDownBox, Image, StateIndicator	All data types	The controls make a comparison between the list elements and the content of the process variables.