LabVIEW returns different results than MAX in response to the same query string

[that_guy]

I am sending an indentical query string to both MAX, VISAIC and LabVIEW, and am getting garbage data in LabVIEW not returned in either MAX or VISAIC. Anyone know whats going on here?

[Dennis_Knutson]

Define 'garbage'. Is the reading incorrect, incomplete, or something else? Is the string indicator from the VISA Read set to hex display or '\' Code Display? What is the command you are sending? What type of connection do you have - serial, serial, etc?

If you could post the VI you wrote after running it, doing a Make Current Values Default, and then a save, it would help to actually see what is being returned.

[that_guy]

yeah, that was grossly uninformative. so I have a TCPIP connection to a spectrum Analyzer. I am querying for waveform data in int,32 format. The data block returned in MAX and VISAIC have the correct header eg. #42204 and data in the specified format . However, in LabVIEW, the data block is without the #, and the block contains int 32 data, ascii data and possibly a third data format.

hope this helps

[that_guy]

Did you wanna see the bd? I dont know how to post images.

[Dennis_Knutson]

The actual VI would be better with some data as I mentioned. You can attach a VI or an image by clicking the 'Browse' button next to the attachment field right below the message body here.

What's the make and model of the instrument? Did you try to find a driver already written for it?

[that_guy]

Its an Anritsu MS2717B. I am actually writing the driver for it. Its a new instrument, just released.

So, this problem is showing up in other VIs, now that I'm testing extensively. Its the most bizarre thing ever. some fetch measurement VIs I just ran did the same thing......inaccurate results only in LabVIEW(7.1).

[Dennis_Knutson]

Since you didn't include the results from the VISA Read, I'm not sure what else I can say. It would be nice if you created a string indicator for the VISA Read output so someone can look at the raw data. Below is the fetch function for the 2721 model. The first Scan From String has a #%1d yours is just %1d. You might also want to bump up the number of bytes to read just in case you are not emptying the buffer. It doesn't hurt anything to put some very large number there.