VISA error BFFF003E USB-RS232

[finko]

Hello, I try to communicate to a HP34401A DMM via RS232. I use a WhiteHeat USB-to-RS232 converter with 4 RS232 connectors. They are known as COM7 to COM10 (in NI-MAX ASRL4 to ASRL7). When I send a Basic I/O "*IDN?\n" I get the right answer but the error 0xBFFF003E occurs immediately. The LabView VISA write.VI also returns this error code. When I use a single USB-to-RS232 converter, everything works fine. Can anybody help me about this error code?

[ryank]

Don't remember the exact error, but I've seen some USB-232 converters return errors when you try to configure certain serial settings. Try checking to see if the VISA Configure Serial is returning an error. Another, perhaps not ideal, solution is just to ignore the error. If the communication is really working properly, there may just be something out of specification which is confusing VISA, you could always just ignore the error (call clear error only if the error code is equal to that error).

Regards,
Ryan K.

[echarry]

Hi all,

I get the same error however using USB raw with a microcontroler from Freescale. I can ask for the USB descriptors fine, however if I press the command to read them constantly, I receive this error.

And the error goes to the point of needing to deleting the driver and reinstalling the whole thing again (inf file), so that VISA can recognize it again (in fact, in the system folder it remains there with the exclamation sign).

Does anyone have any idea?

Thx!