What does the error "VISA Status code: bfff0015" mean?

[Steve G]

When trying to setup an instrument in the Instument I/O Assistant, I received the following error when trying to Read and Parse the data, "Timeout expired before operation completed. VISA Status code: bfff0015."

I am trying to read data from a Beta/Lasermike Benchmike, model# 183. I believe the instrument is setup to COM2 correctly, as I have been able to use a different software package to verify that the com port is receiving the signal when sent.

[Dennis_Knutson]

Sounds like you're not reading the correct number of bytes from the instrument or not reading any at all. You may have the cable for the instrument but how did you write the program? Did you init the comm port in your program? Does the instrument require a termination character and are you sending it when you request data?

[RJM]

As mentioned, you are probably trying to more data than what is actually at the port and the VI call is timing out - look at VISA.h and the code you are seeing is the TMO (timeout) code.

I don;t know of a way using VISA to see how many charc are at the port, so I just ignore the return error in some cass and use the retCount of the read call.

rjmiller

[Dennis_Knutson]

VISA Bytes at Serial Port tells you how many. It's on the Instrument I/O>Serial palette.

[RJM]

Yes, I'm sorry I was switching to my CVI hat using the C entry calls for VISA. Is there an equivalent C call for the VI?

rjmiller

[TommyTestBoy]

Serial communication with a message-based instrument can be difficult to get setup. You may have already tried this - but I would confirm that your COM port settings correctly match the configuration of the instrument. You can do a quick check by clicking the properties button next to the instrument selection combo box in the "Select Instrument" Step in Instrument I/O Assistant. Hope this helps. If you still have trouble, let us know what command you are sending and the what the response should look like.

[tsheikh]

The last time I got the error message was when I had terminated the command with \n (carriage return). Try \r (line feed).

[Dan_Mondrik]

RJ:

Use viGetAttribute(vi,VI_ATTR_ASRL_AVAIL_NUM,&nBytes);

Dan Mondrik
National Instruments