Data acquisition via Oscilloscope

Thread Starter

RHO011

Joined Aug 23, 2021
6
Hi, I am am trying to record my device's voltage change due to heating with an oscilloscope. I have set the average acquisition mode. When I save the recorded data and export it as CSV format, I can only see a single frame data in my saved file. I can not find the changing voltage, no matter what setting I try or how many frames I record, my scope only saves a single frame to the exported CSV. How can I overcome this issue?
 

KeithWalker

Joined Jul 10, 2017
2,053
A little more information would make it much easier to suggest a solution to your problem. What is the make and model of the oscilloscope you are using. What device are you exporting the data files to, using what interface and what software? What is the signal you are monitoring?
 

rsjsouza

Joined Apr 21, 2014
335
In addition to @KeithWalker 's comment, the brand of the oscilloscope will tell you how much memory it has to store the voltage variations. This is mostly useful for sub-second fast transients. A slower voltage change, however, will probably be better served by a multimeter with logging - some models can store thousands of samples inside and, in the case of a cheaper UT61E for example, can export it directly to a PC.
 

tautech

Joined Oct 8, 2019
217
Hi, I am am trying to record my device's voltage change due to heating with an oscilloscope. I have set the average acquisition mode. When I save the recorded data and export it as CSV format, I can only see a single frame data in my saved file. I can not find the changing voltage, no matter what setting I try or how many frames I record, my scope only saves a single frame to the exported CSV. How can I overcome this issue?
Long timebase setting of seconds/div and averaging OFF with a HiRes or ERES setting if your scope has one.
If absolute values don't concern you and you only need see the change AC coupling and mV/div settings can be used.
 

MrChips

Joined Oct 2, 2009
24,642
If TS wants to record voltage change over long time frames (longer than seconds) then input coupling should be set to DC.
 

tindel

Joined Sep 16, 2012
817
Oscilloscopes are a poor choice when looking at data over long periods of time.
You might need a 'data logger'... it takes data for long periods of time at slower sample rates (1Hz or so).
If you're on a budget, I've successfully used MSP430's to make datalogging measurements for as much as a few hours. I'm assuming Arduino could do this as well, and there's probably already a library and website help set everything up.
 

Thread Starter

RHO011

Joined Aug 23, 2021
6
Oscilloscopes are a poor choice when looking at data over long periods of time.
You might need a 'data logger'... it takes data for long periods of time at slower sample rates (1Hz or so).
If you're on a budget, I've successfully used MSP430's to make datalogging measurements for as much as a few hours. I'm assuming Arduino could do this as well, and there's probably already a library and website help set everything up.
Thank you so much for reply. The data I want to log is from a very high speed device, thus I need a high enough sampling rate from my data acquisition device. My scope's sampling rate is 1GSa/s. Can you suggest me any data logger with sampling rate higher or equal to 4GSa/s?
 

Thread Starter

RHO011

Joined Aug 23, 2021
6
Long timebase setting of seconds/div and averaging OFF with a HiRes or ERES setting if your scope has one.
If absolute values don't concern you and you only need see the change AC coupling and mV/div settings can be used.
Thank you so much for the reply. I am currently applying your technique but with a averaging on mode. It is helpful for reducing noise.
 

Thread Starter

RHO011

Joined Aug 23, 2021
6
A little more information would make it much easier to suggest a solution to your problem. What is the make and model of the oscilloscope you are using. What device are you exporting the data files to, using what interface and what software? What is the signal you are monitoring?
Thank you for your response. My scope is the BK Precision 2542 (1GSa/S) model. I am getting my signal from a high speed sensor, this is the reason I am considering an oscilloscope instead of usual data logging instruments. I am not using any software for exporting data, I just save frames directly from the scope. Right now I am doing nanosecond tests, my voltage output will increase in a very short timescale and then it will start to drop. I am expecting data like this.
 

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Thread Starter

RHO011

Joined Aug 23, 2021
6
In addition to @KeithWalker 's comment, the brand of the oscilloscope will tell you how much memory it has to store the voltage variations. This is mostly useful for sub-second fast transients. A slower voltage change, however, will probably be better served by a multimeter with logging - some models can store thousands of samples inside and, in the case of a cheaper UT61E for example, can export it directly to a PC.
Thank you for your response. I have replied KeithWalker, there I have mentioned few details of my current work. I need a high sampling rate device for logging my data, that's why I chose an oscilloscope.
 

MrChips

Joined Oct 2, 2009
24,642
Before you venture any further you need to define two specifications.

1) maximum frequency of interest
2) total duration of the recorded data
 

tautech

Joined Oct 8, 2019
217
Thank you so much for the reply. I am currently applying your technique but with a averaging on mode. It is helpful for reducing noise.
You have 2 things working against you, the small memory depth of your scope.....just 4 Kpts and averaging.
With a DSO and the trigger H-Pos mid screen and Trig V-Pos positioned where the start of the waveform will reliably capture it you could use a Single trigger at a timebase suitable to fill the display with the event and grab the data to take to Excel and scale the graph to help suppress the noise.
 

tindel

Joined Sep 16, 2012
817
I’m certainly don’t know your business fully but it’s rare to need to observe a high speed signal for a long period of time. Most applications like this can be satisfied using the scope ‘persistence’ or ‘segmented memory’ modes to make these measurements.
 
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