Ethernet communication with LeCroy wavesurfer 452

[svif]

I need to send waveforms from my new scope "LeCroy wavesurfer 452" to my computer. I have figured out that I need a whole bunch of drivers to do this (visa, ivi, lecroy vicp pasport). I have installed these drivers on the computer, but in MAX it says that i have to have a visa server on the scope. Is it enough to install the ni-visa drivers on the scope or do i need a full labview installation on it?

Is there anything else I need to install on the scope?

Comming from an older scope with GPIB I must say this is not quite as easy to set up - I hate when I have to install a bunch of drivers to make things work!

[alanjb]

Hello svif,

Alan from LeCroy Tech Support here...

Let's take a few steps back... You definitely do not need to install *anything* on the scope. Nor do you need to do anything with MAX! If you are using LabVIEW, there is no reason to use the IVI driver...  What programming language are you using?

Here's what you should do if you are using LabVIEW...  If not, give me a call.

1. Download the latest LabVIEW driver from NI's instrument driver network.  Here's a link to it:

http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=5206

You will find two drivers on this page; one for use in either LV 7.0 or greater, and a "project style" driver for use in LV 8.0.  If you are using LV8, go for the project style driver.  The file that you download is a zip file that contains all of the files along with filepath information;  I recommend using Winzip to extract everything, and make sure that you have the option to "Use folder names" selected.

2. Download the LeCroy VICP Passport and install it on the remote PC.  This is only needed for TCPIP connectivity.

3. Install NI-VISA on the remote PC, either the full or run-time version.

Feel free to give me a call if you have any questions!

Best Regards,

Alan

Message Edited by Support on 04-03-2008 02:34 PM

[svif]

Thank you for you reply.

I have already installed the VISA, the lecroy "passport" and copied the lcwave into a folder under instr.lib on my computer.

I have just now tried "lcwave acquire waveform".

The ip of the scope is 10.12.24.130

-------------------------------------------------------------------

In resource i wrote: TCPIP::10.12.24.130::INSTR

I choose channel 1, on which i just had random noise.

After hitting run i get the error: Error - 1074003951 occurred at an unidentified location

                                                   Possible reasons: LCWVE INITIALIZE

-------------------------------------------------------------

When writing: VICP::10.12.24.130::INSTR

I get a much wilder effect, the scope goes into a "auto setup" mode, activates channel 2 and set trigger on channel 1 (i trigger on external).

And after a few seconds i get this error:

                            Error -1073807339 occurred at Timeout expired before operation completed.

I seem to be getting through to the scope - however something is going wrong!

Am i dooing somthing terribly wrong?

And by the way, i could not find any of the example vi's under ni example finder - I had to open the lcwave.llb file and run the vi from there.

Hope you can help me with this.

Simon

[svif]

I think im making progress.

The vi contained a autosetup vi - Removing it helped.

Also selecting False in the Reset in the lcwave initialize did wonders.

[alanjb]

Hi Simon,

You are definitely on the right track.  For TCP/IP connections, you should use the connection string beginning with VICP.  The example "lcwave acquire waveform" will reset the scope to the "default setup", and perform an autosetup.  You received the timeout either because a) the autosetup took longer than the timeout value selected, or because b) you didn't have a signal in the specified channel that the scope could trigger on. Note that this example changes your trigger source from EXT to C1...

Here's how to make the example work for you...  Go to the block diagram, and wire a False to the Reset? input of the Initialize VI, and delete the autosetup VI.  If you change your trigger source on the scope to External, and you give a valid trigger input, then the example should return data since disabling the reset will no longer change the trigger source.

The examples are located in the Examples function palette of the driver; this is standard for properly-designed LabVIEW drivers.  I don't think that example finder is taylored for non-NI instruments.

Best Regards,
Alan

[alanjb]

LOL you beat me to the punch.

By the way - I submitted a new version of the driver to my contact at NI that includes a bunch of new VIs that are very useful.  I'm not sure when it'll hit the website, but I would imagine that it will be available in the not too distant future.

--Alan

[svif]

Ok I have an additional question

It seems like I can read the y-values in a data format called "waveform data" (1d array), what I cant see is how I get the right time values (x-values).

Also when this runs it changes the trigger to single, i guess this is fine however I would like to be able to set it to normal again just before the lcwave close (im going to do many loops to average the waveform on the computer).

Hope you can help me

Simon

[alanjb]

Hi Simon,

Use Configure Continuous Acquision.vi to set the scope in Normal trigger mode. The way this VI works is a bit odd; I think it wold make more sense to just list the choices of Auto, Normal, Single and Stop, but this particuar approach conforms to a certain standard... In any case, configure the inputs that put the scope into Normal trigger mode.

As for the time values... The driver needs a better approach to getting this data.  In the meantime, send the string inspect? 'horiz_offset' using the lcwave Write.vi, and then read the response with lcwave Read.vi (set the requested byte count to 100 will be fine).  This reads back the horizontal offset, which is the time of the first sample. Successively adding the dt value that is part of the Waveform cluster will give you the times of subsequent points.

Best Regards,
Alan

[svif]

I got most of these things working there is two new issue however.

Sometimes (quite often actually) the program locks up and no more waveforms are recieved. When hitting the red labview stop buttom the program stops after some seconds. When trying to start again the program locks up right away (i can see that since my counter is not starting from 1 again, but stays at the value it was at the lockup). It must be allready at the initialize it locks up since the while loop not runs. The only way to get new waveforms is to stop and restart the DSO program on scope.

I have tried to set the number of samples really low (4) so that hardly and data needs to be transferred to the computer - but that did change things it still locked up.

I added screenshots of the locked program.

Also this is very slow, im triggering at 20 hz, but the computer is not getting waveforms at that speed - even at the 4 samples setting.

[svif]

Went to basics and it seems to work better.