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Multiple Analog displays on one Chart

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Hi I am very new to labview and trying to get display(Chart Graph ) to show several analog inputs as they are input to my PCI-6220 DAQ card.

I have a SCB-68 connector box and am running Ver 8.6 ( have not installed 2009 yet), I have downloaded several different XY multi charts and Graphs but I can not find how to get my analog inputs into a cluster or array. I have tried to lookup how to build an array and Cluster for this with no real success.

I posted earlier, But it was in the wrong location ( still trying to get it right) My problem is I cannot get the data to display on the graph. I have view several different display graph and none I have tried worked.


The graphs I want to build will have 4 to 6 channels each and display a voltage from the PCI-6220.

I have used that DAQ Assistant to help build the input but still cannot get it to run.

The last code I tried looks like this one.


Not quiet right


Thank You

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Message 1 of 8

I'm trying to understand the point of the program. First, you are trying to acquire 100,000 samples from the DAQ Assistant and plot them against 100 points from 3 other numeric operations. What do you hope to see?


Second, making an array from dynamic data is a bad idea. It's just not supposed to be used that way. Actually, I'm of the opinion that dynamic data should never be used but that's another story. You should be appending one acquisition to the previous if you want that single 100,000 sample waveform.


Third, why even have the small state machine? You can do all operations in parallel and not even need a loop.


Lastly, why are you using an XY graph when a normal graph will do exactly the same thing?

Message Edited by Dennis Knutson on 08-27-2009 08:23 PM
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I am a little confused as to what exactly you are trying to accomplish.  Are you trying to input a finite amount of data from one channel using the DAQ Assistant and then graph that on the same graph as your 3 other simulated voltage sets?  How many data points are you trying to acquire from the card?  In order to graph all the data on the same graph, you will need to convert the data from the DAQ Assistant from dynamic data to an array, using a Convert From Dynamic Data Express VI, then you can build a 2-D array with all the data you want to graph and pass that into a Waveform Graph.  As Dennis mentioned, you do not really need a state machine to do this; it can all be done in parallel.  I have attached a program that I created to do what I think you may be trying to do.  It shows how to convert the dynamic data to an array and how to graph all the data sets together.  I hope it helps you out. 



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Christina, Dennis


Will this let me see the data in real time or just a sample of it.

I need to see the data thta is coming in from the input channels all the time in real time.


The file I sent in (mul20xl) was a demo I am trying to figure out labview.

My Project is to display 2 Plots (Charts or Graphs ) of data from a PCI-6220. 

One display is for Pressure and the other id for flow,I have 6 channels in pressure and 4 in Flow.

The pressure are from 0 to 5 PSI differental transducers output or .5 v/PSI.


I donot have any simulated voltage I was trying to use them as a test to see how to get mutlipchannels on one graph.

The last part is to store a 10 sec section of all channels when I press a button.

I was also trying Display only one or two channels at a time in each of the displays.


Thank You



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Message 4 of 8

Both of your charts will show exactly the same thing because you have wired upt the same signal to both. You would need to use the Split Singal function to separate the pressure and flow signals. Each chart will display the data as it is acquired and will display the amount of data you have specified for the chart history. Once the history max has been reached, old data gets dropped. Since you are only acquiring a fraction of the data during each second, obviously you are just getting a sample of the total data that is available.


The Add Array elements makes no sense since you do not have an array. You can't wire both the Boolean and output together. Also, The Boolean has to be inside the while loop to be read while the loop iterates. I think you should probably look at the elapsed time function if you want to save 10 seconds worth of data. If you wanted to use the msec timer, compare it to a value (i.e. time in msec).

Message Edited by Dennis Knutson on 08-30-2009 07:06 PM
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I have split the signals from the DA but hoe do you select which signals go to each display.

I have look through the help file and cannot find the information on this.

Do Ihave the Write to Measurement File correctly position to capture all data line for 10 Secondons?


Thank You



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Accepted by topic author RAL1

I get an error trying to open your VI. Could you actually start using the .vi extension for your files?


I can't look at it but the split signal function is pretty simple. If you have x channels, drag the split signal until you have that many outputs. You would then use the merge signal function to combine the channels you want and then wire the output of those to the charts.

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I finally got the Split and Merge to work

I am now trying to scale all the channels to the proper level on the charts


Thank You  Dennis




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