Data sampling rate on waveform chart

[matdav_17]

Hi guys,

Im really new to labview 2019 and am trying to complete a project. The problem i am having is i cannot seem to adjust the rate that my analog channels plot onto my chart. What i am trying to achieve is a plot every 500ms but it seems to plot at about 3 second intervals. I have tried googling and adjusting just about everything but cannot get the sample time to change. i am using a cdaq-9178 and ni9208 analog card. If somebody could point me in the right direction it would be much appreiated as im feeling quite lost.

cheers

[GerdW]

Hi matdav,

Im really new to labview 2019

LabVIEW2019 is also quite new and not widely used so far. You would be better by attaching a down-converted version of your VI. (I prefer LV2017.)

What i am trying to achieve is a plot every 500ms

Open the "Voltage - Continuous Input" example VI. Set a sample rate of 2Hz and "Number of Samples" to 1. Then start the VI…

Generic suggestion: LabVIEW comes with a huge library of example VIs. Use them to explore features and learn about using VIs/functions…

[matdav_17]

Thanks for the reply, I will try that suggestion now. I have attached a down-converted version as well. 

Thank you

[GerdW · Accepted solution]

Hi matdav,

your VI is wrong in several things:

- you set the wrong sample rate

- there is no error handling after DAQmxTiming

- you don't start the task, but stop it…

- there is no loop in the VI: how do you want to repeat something "every 500ms"?

- the task is defined in MAX: we don't know your MAX settings…

Again: use the example VIs coming with LabVIEW and DAQmx!

[matdav_17]

Looks like im way off! Looks like i need to do some more reading. Thank you for your reply and i will try your suggestions.

Cheers mate.