Using the UDF in an FBD circuit program or another UDF

There are two methods available to configure a UDF library:

The block tree shows the UDFs and UDF library that you have configured:

Note

UDF compatibility

A UDF created on LOGO! Base Module 0BA8 is invalid for LOGO! Base Module 0BA7.

A UDF created on LOGO! 9 (or later versions) is invalid for LOGO! 0BA8 and LOGO! 0BA7.
Note

Not all UDFs can be used in a circuit program. Invalid UDFs appear in the block tree, but are gray. A UDF is invalid if it meets one or more of these conditions:

  • The UDF has no blocks or connectors

  • The UDF has input or output connectors, but no block connections

  • The UDF contains blocks, but no in or out connectors

A circuit program can have at most 16 different UDFs.

  • LOGO! 0BA7 - 0BA8: support at most 64 UDF instances in a circuit diagram.

  • LOGO! 9 and later versions: support at most 128 UDF instances in a circuit diagram.

Within a circuit program, interaction with UDFs is consistent to other function blocks. Double-clicking, for example, produces the following dialog. With this dialog, you can set user-defined names and comments as other function blocks.

Similarly, other blocks can reference UDF parameters, for example, you can drag the input connector of the parameter box of a function block to the output connector of the parameter box of a UDF block:

You can include editable UDF parameters in message texts:

Note

You can not invert the input connectors of a UDF.

If a UDF internally references a parameter that is provided by another already-programmed function block, this parameter appears as "U*" when you use the UDF in a circuit program, for example: