06-05-2024 08:09 AM
Good morning ,
I acquire 6 parameters at 100 kHz; for a duration between 3 min to 50 min I would like to add a list for parameters for the user to choose which signal among the signals of 6 traced parameters; I use while loops for continue and finite mode; I am looking for a functionality that allows me to display the signals after I have stopped the acquisition?
I use an index array, it's not very pretty; once the acquisition is complete I no longer have anything displayed; I tried to get it out of the loop, it doesn't work.
thank you in advance
06-05-2024 08:19 AM - edited 06-05-2024 08:21 AM
Hi Amelie,
@ameletudiante99 wrote:
I am looking for a functionality that allows me to display the signals after I have stopped the acquisition?
I use an index array, it's not very pretty; once the acquisition is complete I no longer have anything displayed; I tried to get it out of the loop, it doesn't work.
When you want to use data after the loop has finished then you need to wire the data out of the loop: THINK DATAFLOW!
It seems you don't save the measurement data anywhere!?
You have been told to learn some basics: did you (yet)?
@ameletudiante99 wrote:
I acquire 6 parameters at 100 kHz; for a duration between 3 min to 50 min
So you collect 6*100kS/s*3min*60s/min*8Byte/S=864MB of data (minimum, upto 14.4GB for 50min): you should write the data to a file. DAQmx can do this automatically for you…
Recommendation: you should NOT handle this amount of data just in memory!
Strong recommendation: don't display all those data in a graph at once…
06-05-2024 08:36 AM
Hi,
50 min * 100 kHz * 6 parameters = 14 Go of data.
I suggest you save the acquired data in TDMS files, so that you can read them once the acquisition has stopped.
Otherwise you will run out of memory.
06-05-2024 08:53 AM
yes, I record on TDMS files I use the daqmxConfigure logging VI;
yes I don't want to display everything on a graph but only part of it to see the shape of the signals
06-05-2024 10:48 AM
Hi Amelie,
@ameletudiante99 wrote:
I don't want to display everything on a graph but only part of it to see the shape of the signals
So you should decimate your data to a reasonable amount.
Example: instead of 100kS/s you may reduce this to 3S/s (min, mean, max), so decimate by a factor of 33k. After 50 mins you will have 9000 points in your graph (per plot)…
06-05-2024 01:10 PM
yes, yes I understand but I want a solution to display the signals outside the loop; I can't program it
06-05-2024 01:49 PM
Hi Amelie,
@ameletudiante99 wrote:
I want a solution to display the signals outside the loop;
Outside of the loop
After the loop you can implement my previous suggestion (decimate, output tunnel).
While the loop still runs: decimate, then use a chart inside the loop…
What do you have problems with? (Mind to take the Training resources?)