oscilloscope traces disappeared. Other functions seem ok.

[vaguy]

We have a virtual bench for which the oscilloscope traces have disappeared. There are no error messages that pop up. Resetting or power cycling has no effect, nor do changing the settings. The trace vertical position cursors are at midscreen, but no traces. We have tried setting the scopes to AC coupling, with triggering on the FGEN start signal which works fine when we observing signals with other devices. It is not that the traces are flat - they are simply not there.

[JoeFriedchicken]

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vaguy wrote:

We have a virtual bench for which the oscilloscope traces have disappeared. There are no error messages that pop up. Resetting or power cycling has no effect, nor do changing the settings. The trace vertical position cursors are at midscreen, but no traces. We have tried setting the scopes to AC coupling, with triggering on the FGEN start signal which works fine when we observing signals with other devices. It is not that the traces are flat - they are simply not there.

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When you say "changing the settings" which settings have you changed? I see you have tried:

• AC vs DC coupling
• edge trigger source

What happens if you change Acquisition modes between Sample and Peak Detect? Does any phosphor appear when you enable Persistence?

Are the plots present in the thumbnail graph?

What does the File » About dialog say about the firmware and application and firmware version?

[WilliamEarle]

A few more follow up questions:

What is your triggering configuration? Auto, Normal, Single, or Stop?

Also, if you run auto-setup, does that resolve the issue?

Regards,

William Earle

Software Engineer

National Instruments

[vaguy]

Autoset does not resolve the issue, nor does any of the triggering mode settings.

We can enable measurements for the scope , and the numbers we get are reasoable for what we are putting in, but there is simply no trace whatsoever - not evan a flat line.

Thoughts?

Regards

Harry

[JoeFriedchicken]

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vaguy wrote:
Thoughts?

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Please answer my questions 😞

[vaguy]

We are on 1.1.

The trace did not show up in the thumbnail either.

This happened yesterday, and I tried it on several computers to be sure. Weirdly just now (literally - I am in the lab) I plugged it in after sitting all night and it seems to be fine.

Is it possible that overheating or something like that would be going on?

Regards

Harry

[JoeFriedchicken]

Thanks for the upates 🙂

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vaguy wrote:

This happened yesterday, and I tried it on several computers to be sure. Weirdly just now (literally - I am in the lab) I plugged it in after sitting all night and it seems to be fine. Is it possible that overheating or something like that would be going on?

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So to confirm: you took one VirtualBench to several different PCs and observed missing plots on each PC?

The next time you encounter this, please try changing the Acqusition mode and enabling Persistence and share what happened.

[vaguy]

Wiill do. We have around 15-20 in daily use with 2nd year EE students. This is the first hint of trouble like that.. We have had a few probes go belly up. but that is more likely students' general nature.

Thanks for the help

Regards

Harry

[Inverter]

I don't see in the VB application sw where are the +-*/ maths function. I have just selected the maths trace but I can't find where are the maths functions . Some one has tried to do some measure with maths functions?

[bstreiff]

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@CIUIN wrote:

I don't see in the VB application sw where are the +-*/ maths function. I have just selected the maths trace but I can't find where are the maths functions . Some one has tried to do some measure with maths functions?

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If you mouse over the "Math" label, then a "..." will appear. Clicking this opens up a submenu where you can configure the math channel.