How do I get waveform of both channels (1 & 2) from TDS3xx Series Oscilloscope

[superlyc]

Hi, everyone

I am not an experienced labview programmer. I have task to use Tektronix TDS380 to read the waveform. I found a driver read waveform.vi from instrument I/O. I can read one Channel 1 or 2 at one time now. But how would I read both channel 1 and 2 simultaneously.

Thanks

[JÞB]

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@superlyc wrote:

Hi, everyone

I am not an experienced labview programmer. I have task to use Tektronix TDS380 to read the waveform. I found a driver read waveform.vi from instrument I/O. I can read one Channel 1 or 2 at one time now. But how would I read both channel 1 and 2 simultaneously.

Thanks

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You wouldn't.  Large data sets take some time to actually tranfer over the bus so, users would begin to pound on the mouse if they wrote a "multi-waveform" read.vi    And then, theres that how many points before the timeout expires issue too so the driver was written to fetch only one waveform at a time.

[I'm sure it took the IVI Consortium weeks of debating to present the current approach]

[Dennis_Knutson]

The very design of instrument communication is sequential. For simultaneous transfer, you would need 2 separate GPIB ports and in most cases, a waste since what is really important is the ability of the instrument to capture channels simultaneously.

[superlyc]

So, there's no way for me to get what I am looking at on the screen of the oscilloscope?

[Dennis_Knutson]

Of course you can and I thought you said you were already doing that. You simply cannot get both simultaneously. You just do a fetch of channel 2 so you do not initiate a new acquisition. The graph display on your front panel should look exactly like the scope's display.

[superlyc]

Do not initiate? I will try that. Thanks

[Dennis_Knutson]

The fetch waveform function on the palette does not call initiate so you can simply do what I said to do.