interface between labview and agilent 33250a gives error

[boogiewuggie]

I desperately need help hooking up Agilent 33250a function generator to labview using GPIB-USB connector from prologix (http://prologix.biz).

So far, I've downloaded the drivers for Agilent 33xxx and whenever I initialize the device, it gives me the following error:

Error -1073807246 occurred at VISA Open in Agilent 33XXX Series.lvlib:Initialize.vi->Agilent 33XXX Series Generate Standard Waveform.vi

I am just using a simple example that NI created (agilent 33xxx series generate standard waveform.vi).

In MAX, I see that my cable is connected to COM7 and it shows under Devices and Interfaces/Serial & Parallel / COM7. (ASRL7::INSTR)

I don't see any VISA component under Devices and Interfaces in MAX though, and I am not even sure if it should.

When I press "OPEN VISA test Panel" for COM7, go to viWRite tab and execute *IDN?\n, I get  return count = 6 and return status = 0. (from some post, I heard that this means cable is actually plugged in... but who knows.)

I've followed numerous guidelins from labview for hours and I just need someone to guide me through step by step from the beginning, because none of the 'guidelines' actually helped.

What I am trying to do is very simple. I just want labview to change the phase offset of a signal from Agilent 33250a. However, I cannot even initialize the device. (When I pressed Highlight Execution button on labview to simulate, the error seems to occur at Initialize block from Agilent 33xxx library).

Could someone give me a detailed step by step instruction on how i should install drivers to get this going? I'd be very grateful.

[Dennis_Knutson]

The error message indicates you have some other program open (i.e. MAX) that is using the port. Close it.

The report of the number of bytes writtren does not indicate anthing about any connection. If you know of a post that says otherwise, provide the link so it can be corrected.

You do realize the driver will have to be modified to use the prologix. Do a search to see what is involved.

Don't understand some of your other statements. First you say the com port is listed and the next line you say nothing is. Either the com port is listed or it's not. A com port is a VISA resource.

[boogiewuggie]

Dear Dennis,

thanks for your comment.

i don't understand your statement when you said

"You do realize the driver will have to be modified to use the prologix. Do a search to see what is involved."

Could you elaborate a little?

Thanks for your reply!

[Dennis_Knutson]

Do a search for 'prologix' needs an explanation? The FAQ on the Prologix web site mentions this as well.

[boogiewuggie]

I've checked the prologix site and downloaded all their drivers already. their Labview examples use custom vi blocks and it works fine when I use theris but I am trying to use the ones from  agilent 33xxx library and these ones are giving me errors at initialize block

[Dennis_Knutson]

And as I mentioned, the error has everything to do with another program using the port. It is the OS that is blocking VISA and causing the error.

[boogiewuggie]

Dear Dennis,

Thanks. Now the function generator at least beeps.

But the problem is that "error generated by remote interface command" keeps showing up on the function generator's screen.

The weird thing is that I am merely using the example vi from NI.

[Dennis_Knutson]

And the example was written with a real GPIB controller.  If I remember correctly from one of the posts that show up when you do that search, you have to add a termination character.

[boogiewuggie]

Dear Dennis,

Thanks for the help so far, but I am pretty new at this (labview and everything else) and don't understand much about GPIB. I did the search and read posts about termination code, and one of the post (i think it was actually yours) says I have to append the commands by CR/LF. This is what I did to add the termination code, but since CR and LF are two seperate characters, I am not sure how to go about doing this. Sorry for the newbie question.

Also, since the cable is not really GPIB, but a virtual port, does this mean I cannot use the blocks from agilent 33xxx library?

Thanks

[Dennis_Knutson]

To append CR/LF, you would have to find each every VISA Write and use the concantanate string function on all the existing command strings.