where can I get deatils about break point?

[sukhiray]

where can I get deatils about break point?

 how it works? what is its functions? etc

[altenbach]

A breakpoint is a debugging tool that will pause execution when the code reaches it so you can inspect the current data. 

I assume this is a Mathscript question and not a LabVIEW question.

I also assume you are using LabVIEW 8.6, because in earlier versions breakpoints were not supported inside mathscript nodes.

Have you read the relevant manual pages?

Managing Breakpoints

Using the LabVIEW MathScript Probe

Do you have a more specific question?