Communication crashes with blue screen

Hi All,

I am developing a user interface using USB communication. I have to read large number of bytes(40000 bytes) from the port. I divide this task by sending query multiple times. I have attached the application. In timeframe VI depending upon the timeframe I will send the query in read the reply. 

The communication is properly takes place untill I change the timeframe value to 10 ms. It will read the whole 40000 bytes but not in one go. I will send that querry 20 times to that port. I am using LabVIEW Professional Developement syatem Windows 7 32 bit.

Please help me out with this problem.

Reagrds,

Manisha