Hello Vivian,
In the future I suggest you post to the LabVIEW forum for questions about the Simulation Interface Toolkit (SIT) your post will get more visibility from the LabVIEW community. This forum is specific to the LabVIEW MathScript feature, which is unrelated to SIT.
SIT installs many examples and has a great How To section in the help which walks you through creating a model, host VI and controlling your simulation, I suggest your look through these topics. If you have a more specific question, again, please post to the LabVIEW forum so that it can be seen by the appropriate community.
I hope this helps,
Regards,
Angela M
Product Support Engineer
