Hp 33120A initialize .vi file

Hi  All

I am using a HP 33120A wave generator to run my vibrator. the vibrator is running well without lab view program, now when I try to control wave form generator using lab view program it gives some jurk sound if I use initialise .vi function, but when I initialise first and then use the same program the vibrator is running fine. 

Can anyone tell me , whats the problem with this function.

Thanks and Regards

Ashish