05-04-2025 10:06 PM
Hi everyone,
I'm currently working on a school project that uses LabVIEW.
Basically, the goal of my project is to measure battery voltage and display the data in a table and a graph on the LabVIEW front panel.
Once the data is stored in the table, I want to extract the voltage values and display them in an XY graph with two plots:
Plot 1 shows the relationship between cell number and its voltage.
Plot 2 is a reference line at 1 volt, which marks the minimum voltage for a cell to be considered good.
The problem is, based on the VI I made, the graph isn't showing the voltage values from the table.
Does anyone know what might be wrong? Or maybe someone could help me fix the VI?
Thanks in advance!
05-05-2025 01:06 AM
05-05-2025 01:09 AM
Hi Me,
@Me.03 wrote:
The problem is, based on the VI I made, the graph isn't showing the voltage values from the table.
Does anyone know what might be wrong? Or maybe someone could help me fix the VI?Thanks in advance!
05-05-2025 01:29 AM
Here's q quick simulation draft using a table and a chart. Maybe it can give you some ideas....
05-05-2025 02:08 AM
Thanks for your reply.
But I got a bit confused when I tried running the VI you shared.
1. In my case, the data from VISA Read is still in string format, but the Waveform Chart needs data in double (DBL) format.
2. Also, the graph in your example uses time as the X-axis, but in my project, I want the X-axis to show cell numbers instead.
As far as I know, Waveform Charts only support time on the X-axis, which is why I decided to use an XY Graph.
Sorry if I misunderstood something. I’m still new to LabVIEW and currently learning to get the hang of it.
05-05-2025 02:13 AM
Hi Me,
@Me.03 wrote:
1. In my case, the data from VISA Read is still in string format, but the Waveform Chart needs data in double (DBL) format.
2. Also, the graph in your example uses time as the X-axis, but in my project, I want the X-axis to show cell numbers instead.
As far as I know, Waveform Charts only support time on the X-axis, which is why I decided to use an XY Graph.
@Me.03 wrote:
Sorry if I misunderstood something. I’m still new to LabVIEW and currently learning to get the hang of it.
LabVIEW comes with a huge example library, and there are example VIs for charts and graphs…
05-05-2025 02:51 AM
Is it correct to use the Fract/Exp String To Number function? Because when I tried using it, the VI gave me an error.
Based on the image I attached, the point where X = 2 (the second data point) doesn't seem to be at the correct voltage position. Is that how it’s supposed to be, or did I misunderstand something?
05-05-2025 04:11 AM
Hi Me,
@Me.03 wrote:
Is it correct to use the Fract/Exp String To Number function? Because when I tried using it, the VI gave me an error.
Based on the image I attached, the point where X = 2 (the second data point) doesn't seem to be at the correct voltage position. Is that how it’s supposed to be, or did I misunderstand something?
05-05-2025 05:33 AM
Sorry if I confused you, Gerd. The screenshot I attached earlier was the result from the example VI that was provided previously. However, when I applied it to the VI I created, the graph did not appear as it should. Here, I’m attaching my VI and a screenshot of the graph from my VI when it is run.
05-05-2025 07:04 AM