LabVIEW Program communicating with a serial port freezes randomly

[hrwang]

I had the similar problem. I am reading a balance with a serial RS232 port (converted to a usb port). I had the same program, run on the same computer (win7) about a year ago. Never had troubles by running it from time to time for almost a year. Then a couple of months ago, people stopped using this program, and dessembled my hardwares. Recently, I have to put everything together, rewrite the program, basically the analogy inputs outputs. I didn't touch the serial part of the program. When I run it again, funny things happened. My program didn't respond after about 30 minutes, it is not frozen, you just don't have input data updated forever. You can close the labview program, and it will show you something like "resetting labview data", which I don't remember clearly. During these couple of months, people might did the update of labview NI max or win7 (I used labview 2012 by the way).

Then I made an exacutable in another computer. This time, the program only runs in less 5 minutes.

Any solutions? Anyway, I am kind of suspect the labview update screwed up. I am trying to reinstall the labview to previous version.

Thanks, 

[hrwang]

update,

I change a USB-serial cable from different company, this time, lasted about 40min, and became non-responding again. I can't stop the program, when I close the program, it shows, resetting program xxxx.vi (xxxx.vi is the program I run).

[JÞB]

Search my tags for USB.  Then go to that control panel device manager and set the power manager options for the USB hubs.

[hrwang]

Thanks. I think changing USB power managment solved my problem. I will keep testing, and let you known if the problem still there. I also remembered in my old setup, I had a usb hub because the usb-serial cable is not long enough, that might conincidently avoid the power managment problem.

Thanks alot