problem with visa 3.2

[Kaustubh_vc]

Hi all,



We have a problem with an application (LV7.1 / WXP) which has to decode serial data from a smart actuator. This actuator sends 8 bytes of data @38400 bps every 3ms (which leaves about 1ms interval between these blocks of data). The application is working perfectly with VISA 2.60 but since we tried it with VISA 3.20, we are constantly getting framing and I/O errors.

We are sure that the problem is coming from VISA, as we ran the software on the same PC with 2.60 and 3.20. The errors come only with 3.20.

An application engineer of NI told us that these errors were not implemented in the 2.60 version and that's why they didn't show up. However, the data that were read by the software with 2.60 were absolutely consistent (no garbage) ! If we filter these errors out, many data are lost, so this is not a solution.

The problems come either in development mode or with an executable file.



Does anyone know about the origin of these framing errors ? The signal is clean, no noise and Hyperterminal does not seem to have problems with it.



If it can help, we can provide a NI-Spy capture file.



Thanks to anyone who can give us some advice on this topic !

[JohnM 64]

Hi Kaustubh,

Yes, either a Spy capture or some specific error codes would be great to continue troubleshooting this issue. Without more specifics, it is hard to say what errors that VISA 3.2 is catching that 2.6 did not. Hopefully we can help you further once a spy capture is posted.

Alternatively, if VISA 3.2 does catch some errors that did not harm your original program, or even errors that your original program depended upon, you could always go back to the previous version and use that one. Just wanted to be sure you were aware of that option.

john m
Applications Engineer