LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Temperature against time

Solved!
Go to solution
Highlighted

Hi, I'm working on measuring temperature against time in labview (of a thermistor). The data comes in as voltage and gets converted to temperature in the subvi. I'm not sure whether I should be using a waveform or XY graph for this. I've attached the block diagram and subvi.

 

Thanks!

0 Kudos
Message 1 of 6
(101 Views)

Hi ehalpin,

 

I'm not sure whether I should be using a waveform or XY graph for this.

You should be sure about your requirements!

So what exactly do you want to display?

 

Waveform graphs are perfect for evenly-sampled data (fixed dt), while XY graphs are nice for data with random X coordinates. (You might also use waveform graphs for non-evenly spaced data when using the waveform datatype…)

 

Why do you need 2 local variables just to display data in the waveform graph?

Best regards,
GerdW
CLAD expired, using 2009SP1 + LV2011SP1 + LV2017 (+LV2018 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

0 Kudos
Message 2 of 6
(74 Views)

Hi, thanks for the reply. I need to log a change in temperature over time so the waveform seems like the best option then! 

 

Local variables were left over from something else I had tried out. Would it be better to just remove those?

0 Kudos
Message 3 of 6
(71 Views)
Solution
Accepted by topic author ehalpin13
07-12-2019 07:00 AM

@ehalpin13 wrote:

Local variables were left over from something else I had tried out. Would it be better to just remove those?


YES!

 


@ehalpin13 wrote:

Hi, thanks for the reply. I need to log a change in temperature over time so the waveform seems like the best option then!


You might want to consider moving the DAQ reading/logging into a parallel loop so it is constantly running and gathering data.  You could change your graph into a chart then and make things simpler.  You should also make sure your DAQ is set to be continuously running at a set rate (DAQmx Timing VI).


There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
0 Kudos
Message 4 of 6
(66 Views)

If you're looking to add a data points to "waveform" over time, it sounds like job for a Chart.  

 

There's an article here on the difference between Graphs and Charts in LabVIEW. 

---------------------
Patrick Allen: FunctionalityUnlimited.ca
0 Kudos
Message 5 of 6
(61 Views)

I use X-Y charts 99% of the time even though they are a bit more cumbersome, I like having complete control over how the data is presented. 

-------------------------------------------------------------------
Unfortunately, most readers of this Forum, including some real Experts, have not mastered the skill of being able to read the code that Posters fail to post. If we cannot see "what you did wrong", we are unable to tell you how to fix it. (Bob Schor 28 August 2018)
0 Kudos
Message 6 of 6
(43 Views)