03-04-2015 02:56 PM
Hello
i am try to make my waveform chart as accumlate data which mean that it will not over write the old measurnents but instead will display all
from the begining of time
can anyone help me?
thanks in advance
03-04-2015 03:06 PM
That is what a chart does. You can set the history buffer by right-clicking the chart and setting chart history length. Unfortunately "from the beginning of time" is not a viable option.
03-04-2015 03:07 PM
A chart will only drop old data once the number of points exceeds the configured history length.
What chart update mode do you have configured?
When was the beginning of time?
What is the sample rate?
How long does the acquisition last?
Maybe you should attach a simplified version of your code so we get a better understanding of the problem.
03-04-2015 03:40 PM
Thanks you all for the quick response i attached my file all i am trying to do is to display interval fo 500 seconds in the waveform chart
how can i do it?
03-04-2015 04:14 PM - edited 03-04-2015 04:21 PM
You're sending 10000 samples to a chart that has a history buffer of 1024 so you will only see the last 1/10 of your main waveform and then the single samples appended after that. Set your Before Lock chart to 10000 points and your Waveform Chart to 60000 (to make room for 500 seconds of data at 100Hz plus the original data). Just right-click > Chart History Length...
EDIT: Oh wait, I just noticed your DAQ read is always writing to the Waveform Chart on every cycle not just appending single points from the PID. I'm not clear on what you're trying to accomplish here by looking at your code since I can't run it without hardware.
03-04-2015 05:39 PM - edited 03-04-2015 05:40 PM
Sorry, I don't have DAQ drivers installed, so I cannot really inspect your code.
Still, there are some beginner mistakes that should be corrected.