Graph doesnt Plot

[Jpibins]

Hello, I have recently started working with LabVIEW for a small part of my bachelor thesis. I need to read data from 5 thermocouples and display each on a separate graph. Three of these thermocouples are controlled by a PID controller and regulate heating pads, which turn on whenever the temperature deviates from 30°C (at 29°C and 31°C).

Now, I have the problem that when I use a DAQ Assistant configured with the 5 sensors and then use an Index Array to access the first entry for the first graph, the graph doesn’t display anything (only for the waveform graph; it works with the waveform chart). Strangely, I can see that data is being read because the y-axis moves when I hold the thermocouple in my hand.

Please help, I hope my problem is understandable, and I apologize if it isn’t.

[altenbach]

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@Jpibins wrote:

Please help, I hope my problem is understandable, and I apologize if it isn’t.

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No, it is not. A graphical program cannot be described well in words alone.

You need to show us your code. Maybe you are only graphing one point so make sure to use the correct plot style. A line requires at least two points, for example.

[Jpibins]

Yeah thought so, dont know why i didnt attach the file tbh. Here my file and thanks for the fast answer (its not finished yet im currently figuring everything out, but its honest work 🙂 ). 

[altenbach]

As suspected, you are only graphing one point. What do you actually want to see? Inly charts maintain an internal history of the last N point. Graphs only show what's in the wire.

Why do you branch the dynamic data wire and convert it to an array twice in parallel? Once is probably enough. Also, index array is resizable. Most seasoned programmers stay far away from express VIs and dynamic data, but why not just split the signal?

Using "from DDT" to convert a scalar to an array makes no sense whatsoever.

Why don't you use the currently disconnected stop button instead of using a switch with latch action. That's not natural.

[Jpibins]

Hey, I want to continuously map my sensor and update it in real-time using a chart. I'm working with an index array since I've assigned the DAQ Assistant to 5 thermocouples, so I get an array, right? I would now address each individually using the index array and create a separate graph for each. I used the DDT (Dynamic Data Type) because I couldn't connect it otherwise, and LabVIEW required me to do it this way. I added the stop button part simply because I saw someone do it in a YouTube video. I want to emphasize that I'm really a beginner, so it might be possible that I'm doing everything wrong.

[altenbach]

Don't use a graph if you want a chart.