faulty communications

[Dana T]

I am sending out 8 bytes of data to a product and it should return 112 bytes of data. sometimes it works and sometimes it does not work.

I used a qbasic program to do the same test with the same hardware and it works every time.

Why is LabVIEW comm so unreliable?

How to I fix this problem?  

[Dennis_Knutson]

LabVIEW is reliable but perhaps your program is not. What kind of communications are you using? Is it GPIB, serial, or something else? When you say, "sometimes it does not worl", how does it not work? If you could provide some details on your program (post your VI, please), and what it is that you're talking to, it would help.