labview eval formula node with VI

[zmarcoz]

The VI has been attached this time
I really have no idea why it doens't work
please help
thanks

[altenbach]

It seems to work fine. Make sure that all inputs are defined. I have attached your example showing some simple inputs set as default values, just run it and see.
(E.g. remember that "variables output" is actually an input that needs to be defined!)