How to plot temperature and voltage using Mixed Signal Graph

[mzlhb]

Hello,

I am using the NI cDAQ-9178, module NI 9214 (temperature) and module NI 9201 (voltage). My program allows the user to select from 3 different tasks, Temperature Masurement, Voltage Measurement or both. When selecting the task for both Temperature and Voltage Measurement, I was plotting all channels onto the same graph. I've been asked to separate temperature and voltage channels and plot onto one split graph, using the same x-axis. I've tried stacking, but could not control where each channel plot went. I think that the Mixed Signal Graph would work best. All is working and all channel data is saving to files, but my plots are not showing on the graph, although I can see the graph scale numbers changing. I think that I may be using the cluster incorrectly. Can someone tell me what I am doing wrong?? I've selected the "Plot Visible" option, but plot still is not displayed. I have attached a zip with all necessary VIs to run my program. The main VI is "Voltage_Temperature_SingleTask_Measurements_MAIN.vi" ... but all must be downloaded for the program to work. Please help ... thanks. 

[aputman]

I can't open your VI but here are a couple of thoughts (if i am understanding your question correctly):

1. Is Autoscale turned on for your Y-Axis

2. Is your plot color transparent?

[mzlhb]

I can't open your VI but here are a couple of thoughts (if i am understanding your question correctly):

1. Is Autoscale turned on for your Y-Axis

The Y-Scale is grayed out, so I cannot select AutoScale ... but if I go into properties, AutoScale is checked

2. Is your plot color transparent?

I don't see any transparent options, when I right click and select "Color". My current default colors are blue and red.

Try the zip file now

[GerdW]

Hi mzlhb,

you have just one (1) sample in the waveforms you read from DAQmx device, so the graph will show "nothing" according to <our plot properties.

Change the plot style to show dots insteadof/additional to interpolation lines -  or read more than just one sample per DAQmxRead!

WTF you are doing with this SplitSignal function on your waveform array? Why not use a simple IndexArray?

[mzlhb]

GerdW:

WTF you are doing with this SplitSignal function on your waveform array? Why not use a simple IndexArray?

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GerdW,

I'm quite new to LabVIEW, so I don't know how to use the Index Array in this application. There is a NOTE in the CONTEXT HELP for the Mixed Signal Graph that states that the bundle must be used. I couldn't figure out another way to separate my voltage and temperature, except with the split signal function. Can you explain how I should use the Index Array in this case. I connected the Index Array to the output from the DAQmx Read, after reading your post and everything stopped working. Thank you

[GerdW · Accepted solution]

Hi mzhlb,

I only complained about the expressVIs.

Why not use simple IndexArray function to get bots waveforms from your waveform array? (I simulated your DAQmxRead with SigGen functions.)

[mzlhb]

Thank you GerdW. That worked perfectly