Using SignalExpress for data logging on oscilloscope Tektronix TDS2022 via usb

[Travis-E]

Do you have a second ocsilloscope that can be used to try and recreate the ssame behavior? I would like to see if the issue is specific to the device or if there is a problem with the software. 

-Travis E

Applications Engineer

National Instruments

[DrElectrode]

I am continuing this thread with the same issue. In my case, I am using a Tektronix TDS2014B. The story is the same. The scope free runs just fine under it's own control but under SignalExpress control it repeatedly triggers creating a recording that is discontinuous bursts of data. The scope's memory is not sufficient for the duration of some tests that I need to run, so, I was hoping SignalExpress was the answer. By the way, this is a recently installed instance of the SignalExpress software running in 30 day trial mode.

[Nathan-P]

Just to verify, which version of SignalExpress are you using?  The Tektronics Edition?

[ye_zhao]

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@Nathan-P wrote:

Just to verify, which version of SignalExpress are you using?  The Tektronics Edition?

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I have similar issue with my Tek scope 2024B and LabVIEW SignalExpress 2012.

The scope can be controlled by SignalExpress. But it fails in continuous data logging.

For example, two channels, Ch1 is 1kHz square waveform, Ch2 is nothing connected, always zero volt.

The data logging cannot capture the full scope but just a few discrete signal. Completely useless...

I will try to use SignalExpress Tek Edition and see if I can solve the problem. I will update later.

Thanks.

[ye_zhao]

This is a follow-up.

[Problem]

To my knowledge, SingalExpress - Tek version has similar issue as SignalExpress: a long processing time between each triggering, leading to a big data gap (blank data). Therefore, it is impossible to get a continuous data logging.

[Solution]

To solve this problem, I turn into LabVIEW 2012, which has much faster processing time (efficient codes) than SignalExpress. Tektronix provides the driver for LabVIEW and a complete family of building blocks (see attached files) for my Tek scope TDS 2024B. It's easy to install the Tek driver in LabVIEW. Remember to install the VISA on your computer. A few examples are also given so it's really straightforward to get it work.

[Notes]

1. the data will be collected exactly the same as what's shown on your scope's screen. To be specific, your scope keeps being triggered, and the data for the ongoing snapshot of the screen will be transferred to LabVIEW for processing. LabVIEW will merge every snapshot together to make it "continuous" and store it in your hard drive.  For this reason, to collect a continuous ac signal, it is your job to ajust the time base so that you can have correct number of periods on the screen, so the total saved data will look continuous in computer. Please change the time base accordingly during data logging.

2. Although the sampling rate is 2GS/s for this specific scope TDS 2024B, theRecord length is  2.5k points at all time bases on all models.

3. It may require a little bit work to add time axes on the data signal in LabVIEW. Or you can easily post-process it in Matlab or other software, since the time x0 and delta x are both given by LabVIEW and scope.

[example]

An example of measuring ac signal from a Variac: 60HZ. (using differential probe, probe x50 voltage gain). Both continuous and discontinuous data logging are attached.

Hope it helps.

Ye Zhao

[steveabode]

Hi all

I've experienced the same problem with my work's TDS2014B-  I believe the 3000 series have a higher transfer rate than the older ones and probably work better with the Tek version of Signal Express-  I've taken a different tack than the expensive LabView full edition route-- my project was to find noise that was affecting a current measuring circuit, so I have been using the 2500 point data logging that the unit sends out their very basic OPENCHOICE software to grab ten different sets of data taken from one or more probe points-  in this way, and even though it's only a snippet of data each time, I have been able to create a 25000 point analysis that shows very well where the problematic noise is occuring, realistically with four probes that could equal 100k of data and with parallel comparisons across the channels i feel it's "made the best of a bad lot"  😉

Happy probings, one and all!