Can anyone tell me how I can create a function block that has a variable number of inputs? For example, in the online documentation for V2.3 it says:

'Insert' 'Input of box' in CFC

Shortcut: <ctrl> + </ctrl>

This command is used to insert an input at a box. The number of inputs > is variable for many operators (e.g. ADD can have two or more inputs).

To increase the number of inputs for such an operator by one, the box > itself must be selected

Is it possible for me to create a function in my own library that has the same type of functionality, where the user can select the number of inputs?

No impossible as the compiler looks at how many inputs are used.

There is a work around it.

when using AND for example

You can make your own functionblock with many inputs and the unused ones fill with true.

result:=inp1 and inp2 and inp3 etc.

you must declare all inputs

inp2:bool:=true; will not work.

You can create a functionblock with "variable" amount of input by using an array and an index number

FUNCTION_BLOCK VarInput
VAR_INPUT
   awInput:ARRAY[0..255] OF WORD; (*255 free asignable inputs*)
   byAmount:BYTE; (*for use in a for loop to know when to stop, for example*)
END_VAR