Tektronix MSO2014b - connection drop-out

[David_NMRSA]

Hi Everybody -

I am running LV2015x86 on Win10, connecting to a Tektronix oscilloscop, MSO 2014B using NI-VISA 15.0.

The MSO has the latest firmware (v 1.52) and will work for me, through configuration of timebase, channels, etc, and reading waveforms and various measurements. All works fine.

However, there will occur an error while reading from the MSO (measurements, no waveforms) wherein an error is flagged and it will no longer re-connect. The error I receive and capture shortly after it occurs is:

Error -1073807339 occurred at VISA Read in Tektronix DPO MSO 2000 4000 Series.lvlib:Error Query.vi->Tektronix DPO MSO 2000 4000 Series.lvlib:Fetch Waveform Measurement.vi->MSO2014B_connect.vi->sub_MSO_getWaveforms.vi->Main.vi

Possible reason(s):

VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed.

I'm not sure where the timeout is occuring or what is generating it, but it doesn't appear regular or consistent with anything I do. Which is why it all seems to work fine and then eventually stops.

The device itself hasn't been 'tested' by NI, as per the infromation regarding the instrument drivers (not to be confused with IVI drivers - tried those; not fully functional and doesn't quite work).

Has anybody come across this kind of thing and/or can recommend a suggestion on what may be happening?

I have attached a snippet of the code (FGV) where the error appears to be occuring. I believe the read error occurs at the first read (of the two there), at the first selection box. This is because the indexed cluster array of the For loop comes up empty. What I find incredibly confusing is that the empty empty isn't captured until the FGV has been closed (and I test it the same way straight out of the subVI).

I have included various captures in my code so it doesn't look pretty.

To give you context on what is being done:

* a stepper motor moves an RF sensor

- for each of the 3 channels:

* I read in the Vpp of the waveform on the MSO

* check to see if the Vpp is within the vertical range - adjust if not

* read in Vpp and other measurements I had selected prior to starting test

* move stepper to next position

* repeat

[Chantastic!]

Hi David!

Based on the error message, I believe the error may be occuring within your Fetch Waveform Measurement.vi in the code snippet you provided. The error code suggests your VISA read function is timing out. Since I dont' have your setup or data, can you tell me what happens when you run the just fetch waveform measurement VI? 

[David_NMRSA]

Hi Chan!

Do you mean running the subVI on its own, without the rest of the code in the snippet? Well, I think I have but not entirely sure.

I suppose I could run the subVI and then run the Error Query.vi continuously until a timeout error occurs.

i'm on holidays but will stop back into work and give it a quick test. Watch this space!

[Chantastic!]

You could also open the block diagram and then probe the error wires running into and out of the sub VIs where you think the error might be occuring! I'd start at the VISA Read Sub VI. 

[David_NMRSA]

yeah, I did all that. The error was definitely coming from the Read Waveform subvi. There isn't much in it, if I remember correctly. I popped into work to have another look but found that another colleague with LabVIEW withdrawls had been at it - made some changes that were a touch confusing and I walked out :P. I'll try again when everybody comes back from holidays! Thanks.