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updating graph

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I am trying to get the labview software to simply use an inputted signal and display it over a set amount of time or to continually updat while not overwriting the previous data aquired. I have the signal from the DAQ card running to the graph fine but at the moment it only runs for a certain time to receive the samples and every time replaces the data held with the knew data aquired. I want to keep the previous data either on the graph or in some other way.


Any help greatly appreciated,

Christopher Boswell

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Message 1 of 6
Accepted by topic author goblinhat

Hi Christopher,

you have to store the old values. Use a shiftregister to do it. If you get a waveform, then you can use the "Append Waveform" function to create a waveform with all your data.



Message 2 of 6
Your other option is to use a chart. A chart has a history buffer and does not require you to use a shift register. You would however, need to set the length of the history to be large enough to keep all of samples in memory.
Message 3 of 6

Thanks for the replys guys. I am trying to use the Waveform chart method. The problem is I can only get it to display 5 seconds no matter how big i make the chart history length. Presumably it is saving the previous waveforms but not displaying them - how do i extend the chart to display the old waveforms?


Thanks in advance,

Christopher Boswell

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Message 4 of 6

Just thought I'd add that I'd like to display at least 60 seconds on the chart while being able to go back through older chart waveforms if possible.


Christopher Boswell

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Message 5 of 6
Nevermind actually I've found out how to adjust the time usingg the graph pallette, thanks for your help.
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Message 6 of 6