VISA GetInQLen

[wthorson]

  In the old RS232 communications I would use GetInQLen to determine the amount of data in the buffer, is there something similar in the VISA commands?  I am receiving data between 4 and 30 bytes long.  Below is the code I have configured to read in 4 bytes.  Is their  a way to modify it such that it could very to depending on how many bytes are in the Buffer?  I am assuming I am missing something simple.

 // Parse a binary string
 ViNullChk(RxPacket = (ViBuf)malloc(4));
 ViErrChk(viScanf(resourceName, "%4c", RxPacket));

Thanks,

[RobertoBozzolo]

I normally don't use VISA, preferring the traditional RS232 library, but I've found an attribute that may help you:

viGetAttribute (handle, VI_ATTR_ASRL_AVAIL_NUM, &bytes);

[wthorson]

Thank you for the information, that is what I was looking for.  But as you stated I am thinking I will probably go back to the standard RS232 functions, I haven't seen the benefit of VISA for my applications.

Thanks.

[MilanV]

Hallo Roberto,

VI_ATTR_ASRL_AVAIL_NUM flag can be used in order to determine the amount of data in the input serial asynch. COM buffer, but what about determining number of bytes in output buffer ? Is there any VISA function which query number of bytes in output buffer ?

BR,

Milan.

[Eric_K]

Milan,

With a question like this, the best approach would be to make a new thread for your new question, which I can see that you have done on this duplicate post.  Once you have done that, there is no need to post on 9 other threads to ask the same question.  Please see the duplicate post for the answer that SFK has given.

Thanks,

Eric K