You can create an empty UDF from the File → New menu command or the tool bar.

A UDF has a rectangle to indicate its edit area. You can edit the position and dimensions of this area.

Restrictions for a UDF:

• Input (analog + digital): 8

• Output (analog + digital): 4

• Parameter: 8

  Note Not all blocks can be added to a UDF. Items shown below can not be added to a UDF: Inputs Outputs Analog inputs Analog outputs M8 M25 M26 M27 Shift registers PI controllers Data Log Message texts

You can also create a UDF from selected figures. To create a new UDF, select the blocks, right-click, and select "Create UDF" from the context menu.

If the selection includes blocks that a UDF does not support, LOGO!Soft Comfort excludes them from the UDF. If an included function block is connected to an excluded one, LOGO!Soft Comfort creates an input or output in place of the excluded block. If the number of inputs and outputs would exceed the restrictions, LOGO!Soft Comfort does not make inputs or outputs that would exceed the restriction.

LOGO! Soft Comfort creates the UDF and opens it in the UDF Editor: