Change the background color of the button if it is highlighted


  1. PLC
  2. Use libraries
  3. Library placeholder
  4. placeholder

function: The command opens the dialog placeholder. All library placeholders in the project and their current definition of the resolution are listed in the placeholder overview. You can also use this dialog to manage placeholders and specify versions for placeholder libraries (e.g. resolution to a specific library version or to “always newest” / “*”). The version resolution is also possible here for placeholders that are only used internally in other libraries.


  • Context menu of the object References in the PLC project tree
  • Button in the library manager (symbol: )

By default, placeholders are resolved to the "always newest" / "*" version of a library. In the placeholder dialog, you can redirect any placeholder resolution that is used directly or internally in the project to a different version of the library or resolve the placeholder to another library.

Building the dialogue

The dialogue placeholder is divided into three columns.


Name of the placeholder


Name of the library to which the placeholder is resolved

  • Library column in bold:
    The library is in dialogue placeholder Marked in bold if the placeholder is not resolved according to the standard resolution (usually "always newest" / "*"). This is the case when it has been changed to a user-specific resolution. The gap info In this case it is set to "Resolved by placeholder redirection".
  • Change the library to which the placeholder should be resolved:
    By double-clicking on a field in the column Library A selection list opens below the selected line, which you can use to change the library to which the placeholder is to be resolved. For more information, see Changing the placeholder resolution.


Information about the type of placeholder resolution

  • The information "Resolved by library profile" means that a (Beckhoff) placeholder is resolved according to the specification in the library and thus according to the standard resolution.
  • The information "Resolved by default library" means that a placeholder is resolved according to its standard resolution ("always newest" / "*").
  • The information "Resolved by placeholder redirection" means that the resolution of a placeholder in this project has been changed. The standard resolution is not used, but that which the user has set himself and which is saved in the PLC project file.

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