How do I acquire waveforms with Tek TDS3000 scope using Visual Basic and GPIB?

[williamdor]

I've been "working" with Tek customer support to correct a bug in a TDS series 3000 scope sample application over GPIB. The programming documentation is not sufficient to correct and expand the application to be useful. Note: I am not using VISA.

I am trying to get an entire 500 pt. waveform acquisition that captures either the entire scope "face" or from the trigger to right side of the scope face. Their sample code acquires 250 "valid" (the last 250 are zeroes) samples starting at the center of the scope face. The result is a low resolution representation of half your waveform.

The critical part for me is understanding an exact breakdown of their data format for acquisitions of WID
TH 2. I've not found this nor found anyone who can pass such a description on.

I appreciate any light you can shed on this problem.

Thanks -- Bill

[TonyH]

Bill,

I'm not that familiar with TDS3000 scopes, but I did notice one thing in what you said that you might want to look in to.

You want to capture 'the entire scope "face" or from the trigger to right side of the scope face'. The trigger is not necessarily the left-most value on the scope display. All modern digital scopes have a pre-trigger feature that allows you to collect points before and up to the trigger as well as after the trigger. If half of your scan consists of pre-trigger points and you somehow ask the scope for data from the trigger to the end of the scan, you might see the behavior you indicate.

Just a shot in the dark. I hope it helps.

TonyH
Measurement Studio