Define Parameters and Private Variables

For a Function or UDFB, input and output parameters (as well as private variables) are declared in the Dictionary toolbox as local variables of the item.

The Add variable command is used to add these items:

• Input Parameter - Externally supplied, not modifiable within the organization unit.
• Output Parameter - Supplied by the organization unit to external entities.
• Private Variable - Supplied by external entities; can be modified within organization unit.

Figure 1: Parameters and Private Variables

Input and Output parameters always appear at the beginning of a UDFB group.

Pressing the INSERT key when the item is selected adds a private variable.

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• There are some things to be aware of with UDFB parameters:
  

  • UDFB cannot contain parameters being both for Input and Output.
    
  • Simple parameters (scalar type) can be either IN, OUT, or IN_OUT.
  • Complex parameters (an array or structure) should be declared as IN but is systemically considered to be IN_OUT.
    
  • UDFB cannot have more than 32 input parameters or 32 output parameters.
    
  • Output parameters can only be simple Data Types.