Analog Waveform TimeStamp

[kchenphy]

Hi,

    I am reading traces on Ch1 from a Agilent Scope, with the trigger set on the rising edge of Ch4. So I would expect the trace I am getting has zero time aligned with the rising edge of Ch4 (time after that edge is positive, before is negative), just like what the time indicator on the scope says. However, when I call some "read trace" VI to do this, zero time is always aligned with the leftmost time point on the scope screen. For example, if trigger moment is zero and the scope displays from -1 ms to +1 ms. The Labview VI would give me 0 to 2ms, which is anoying since all the time information I am interested in is referenced to trigger moment. You can verify this by hooking a waveform graph directly to the read trace VI. I was wondering if anyone knows how to figure out the correct zero time in Labview. Any input is appreciated. The read trace vi is "DSO7054A Factory Read Trace.vi".

   Thanks

Kuang

[margasan]

Hello kchenphy,

To report issues or provide feedback about  instruments driver, please send an email to instrument.drivers@ni.com. They should be able to help, as you are contacting the developers directly.

Regards

Mart G.

[Dennis_Knutson]

This is the current driver for the DPO7054A and there is no VI in the driver named "DSO7054A Factory Read Trace.vi". Where did you get it?

[kchenphy]

Sorry the vi name is wrong. It is "ag6000a read multiple waveforms.vi"

Thanks

K

[Dennis_Knutson]

In the fetch waveform subVI, instead of creating a waveform data type, try using a regular cluster with x0, dt, and y array - the old standard way to create graph data. You might also want to probe what is actually being written for the timestamp. It is coming from the instrument.