Windows XP Serial Port Problems

[Mluvara]

Hi,

I have an application written in LabView 6.1 that reads incoming data over a common serial/rs232 port of a pc. It has been extensively tested on Windows 98 and now when installed on XP, the serial port does not work. The vi initializes com port settings when loaded, but does not see any of the icoming data. I have been intermittently successful in getting it to read data after opening hyperterminal or installing an uncompiled VI on the system. I believe all the settings are the same on hyperterminal as on my application.

I will be setting up to view the serial port error handler, but in the mean time, does anyone have advice or experiences that could help point me in the right direction?

Thanks for any help that you can provid
e.
Michael

[mikeporter]

If you can talk to the port with hyperterinal, but not LV the most likly cause is either that the settings aren't really the same, or there's an error occuring that isn't getting handled properly--though it could also be something related to handshaking.

Can you see the output from the external device using one of the serial port examples that ship with LV?

Mike...

[Mluvara]

The settings appear the same. All data is incoming, so my program just looks for data at the serial port. I will have to test the LV examples on the suspect laptop (customer's) where the problem is occuring. The application I wrote is not using the VISA serial port driver and are now wondering if I should be...

Thanks,
Michael

[Chris_Rake]

The traditional vi's are not recommended for serial communication - it is possible that things like flow control will not work properly. Please let us know if you continue to have problems.

[Mluvara]

Thanks for the replies. After discussing it over the phone with NI Technical Support (who were very helpful), it came down to some structure problems within my program, whereas it worked within the development environment, but not when built with application builder. All appears to work now.

Michael