updating graph

[goblinhat]

Hello,

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

[MikeS81 · Accepted solution]

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.

Mike

[Dennis_Knutson]

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.

[goblinhat]

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

[goblinhat]

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

[goblinhat]

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