oscilloscope agilent MSO-X 3024A, multi-channel acquisition

[stephenf555]

Hi folks,

Trying to use the 3024A to grab multiple channels of data to LabView. I'm using the provided vi's, namely Agilent 2000 3000 X-Series Acquire Waveform.vi.

It works no problem with channel 1. No other channels will acquire.

I've tried to use the other vi's too and cannot get any data other than channel 1.

The problem appears to be in a VISA read operation within the Agilent 2000 3000 X-Series.lvlib:Fetch Waveform.vi. I have checked the strings VISA writing the setup info before the read, and the only difference is the channel number. 

Any guesses?

Regards,

Stephenf555

[Rhys - AE]

Hi there Stephenf555,

When you mention that no other channels will acquire, does the instrument successfully return flat line data (zeros), do you not receive any communication back from the instrument, or do you get any error messages?

If the problem is a lack of or incorrect communications then you can use NI Spy to capture all of the comms accross your serial ports. Linked below is a page on our website that describes NI Spy and how to use it.

Performing a Good NI Spy Capture for Debugging/Troubleshooting
http://digital.ni.com/public.nsf/allkb/282C5D41E2BA04F2862574BA007803B9?OpenDocument

Before we get too indepth, lets make sure that our software is up to date. What version of NI VISA do you have installed? (You can tell from the Software tab under My Sytem in MAX). I recommend getting the latest NI VISA driver from the link below, but at least be operating on version 4.6.1 or later as I remember that upgrading to this version solved a comms crash with this same agilent instrument for another customer.

NI-VISA 5.0.3

http://joule.ni.com/nidu/cds/view/p/id/2251/lang/en

I'm looking forward to helping out!

[stephenf555]

Hi Ryhs,

Thanks for your reply.

To answer your questions:

I have Version 5.0.3 of VISA installed.

When I ask for more than one channel back, I get a replication of channel 1. For instance, if I ask for 2 channels (it doesn't matter which channels, it can even be channel 3&4), those channels are both populated by the actual data from channel 1. On the oscilloscope screen itself, the channels are displayed correctly. But on the PC, I just get copies of channel 1.

I used the similar example with a previous oscilloscope (Agilent MSO 7000 series) and there was no problem.

Regards,

Stephen

[Rhys - AE]

Hi Stephen555,

I've been having a dig around our records but it doesn't look like we've ever seen anyone with this problem before. Alas, we are unable to piggyback off of any background knowedge, ha!

Would you be able to pass on the code you have been using, and any commands you have been entering into that code? I haven't got any agilent scopes handy in the lab, but I'd like to look over the block diagram.

A step further than this would be to make a capture using NI Spy whilst the incorrect behaviour is present. but lets not use up all your time just yet, we can do that in a afterwards. Just the VI's and all their dependancies would be great for now thanks.

Thanks for your time!

[stephenf555]

Hi Ryhs,

The vi's I've been using are the ones provided on (the labview 2010 version):

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=9E84674573AF6AB8E0440021287E6A...

My problem can be explained by the Acquire Waveform and Acquire Multiple Waveforms vi's.

Starting with Acquire Waveform...it works fine if I choose to acquire channel 1. If I choose to acquire any other channel I get a "settings Conflict" error and I get no response.

With Acquire Multiple Waveforms, if I choose to acquire channels 1 & 2, I get a plot which plots channel 1 twice (overlaid but visible if I increase the width of the second waveform). If I insert a block to save the waveforms to a file, the two waveforms are identical also.

In my testing (don't count on me being correct!) I think I narrowed the fault down to the Fetch Waveform.vi (in public/Data/Low Level/). The process seems to go ok up to this point, with the correct channel chosen from the strings at the top left of the vi. The problem seems to occur possibly in the centre VISA read block (with the 200 input for the byte count) (used breakpoints and did not receive any warnings up to this point). In this block, or possibly the VISA write block next to it, I get a warning that a command was not terminated. I tried adding a "\n" or a "\r" to the end of the associated command but it made no difference.

Regards,

Stephen 

[jjp377]

Hi Stephen,

We have updated the driver below which should address your issues.  If you can please test the driver, so we can release the updates to IDNet.

Thanks

[stephenf555]

Hi Ryhs,

Excellent stuff!!

I tested all the included vi's and they all work as they should.

Thanks very much for the update...this will make my data acquisition a lot easier.

Regards,

Stephen

[Rhys - AE]

Really glad to here that Stephen,

In honesty, all kudos goes to jjp377. Thanks from me as well, couldn't have done it that fast without your help

All the best with your future DAQ.

[stephenf555]

Apologies to you jjp377, in my excitement to check if it worked I didn't spot that the poster's name had changed.

Thanks to you both for your help.

[jjp377]

Thanks for testing the updates and posting your results.  If you have any other issues please let us know.