Command 'Interface editor'

Symbol: ; keyboard shortcut: Alt+F6.

Function: This command opens and closes the Interface editor tab above the visualization editor.

Call: Menu bar: Visualization ‣ Interface editor . Alternatively by clicking on the small down arrow at the top of the visualization editor.

Tab 'Interface Editor'

Scopes

Tab 'Interface Editor'

Symbol:

The tab contains an editor for the declaration of interface variables. The editor behaves in a similar way to the declaration editor of a function block, however interface variables are not initialized.

Syntax

<scope>
( {attribute '<attribute name>' ( := '<expression>' )? } )?
<identifier> : <data type>;
END_VAR

<scope> : VAR_INPUT | VAR_OUTPUT | VAR_IN_OUT
// (...)? : Optional

Example

Declaration in the interface editor

VAR_INPUT
    {attribute 'parameterstringof'}
   sIdentifier : STRING; // String for instance name
   iCounter : INT;
END_VAR
VAR_IN_OUT
    {attribute 'VAR_IN_OUT_AS_POINTER'}
   fbController: FB_Controller;
END_VAR

Scopes

Possible scopes for interfaces of visualizations or dialogs

VAR_IN_OUT

When transferring a structure.

When the visualization is instanced it receives a reference to the current application data.

When transferring a control variable, if the variable is written to when a user input is made. Only then the visualization can write to it.

Note: In the case of dialogs the data are only written back when the dialog is closed.

Hint: We recommend urgently that you use this scope so that the return of values is possible. In addition, no data need to be copied.

VAR_IN_OUT

Pragma {attribute 'VAR_IN_OUT_AS_POINTER'}

When transferring a pointer to a data object.

As opposed to the VAR_IN_OUT scope (without attribute), the variable changes become effective immediately and not only when the dialog is closed.

Note: Use this scope only if the visualization implements a Dialog.

VAR_INPUT

When transferring data that are only read

Note:

If the visualization is executed as an integrated visualization, only input variables of a basic data type (scalar type) may be transferred.

If the visualization is executed as CODESYS TargetVisu or CODESYS WebVisu, then input variables of any data type (including POUs) can also be transferred.

VAR_INPUT

Pragma {attribute 'parameterstringof'}

When transferring a variable (data type STRING) for the instance name of the transfer parameter specified in the attribute.