Customized Malleable VI Does Not Accept a Specific Data Type

Updated Sep 10, 2018

Reported In


  • LabVIEW 2018

Issue Details

I customize a Malleable VI to accept a data type. However when I connect the customized data type to Malleable VI input, the wire breaks. Why does it happen?


A Malleable VI (.vim) is a VI that is inlined into its calling VI and can adapt each terminal to its corresponding input data type. With malleable VIs, you build a VI to perform the same operation on any acceptable data type instead of saving a separate copy of the VI for each data type. You can customize sections of code in a malleable VI for specific data types or force a malleable VI to accept only a subset of the acceptable data types by using the Type Specialization Structure and the Assert Type VIs and Function.

If the Malleable VI doesn't adapt to the customized data type, it is because the Type Propagation detects an error to adapt to corresponding data type. Try following steps: 
  • Check if subdiagram of the Type Specialization structure for corresponding data type contains coding errors.
  • Convert the Malleable VI to Standard VI right-clicking the instance VI and select Convert Instance VI to Standard VI for debugging the code as described in Debugging Malleable VIs.


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