Continuous charts

[Sumeet]

Hi,

I'm new to labview. I'm facing a very basic problem.

I need to measure temperature, and I'm using the 9172 chassis and 9217
module to do that using RTD's. Now, in labview, I added a DAQ
assistant, and set the samples to continuous with a sampling rate of
1Hz. I need to plot this data. However, when I connect a waveform
chart (strip chart) it displays the data for 5 secs, keeps it stagnant
for 5 secs, then displays new data after 5 secs and so on. It doesn't
display it continuously. Also, increasing the X axis from 0 to 20
doesn't help, it still displays data only in the first 5 secs of the
graph (and refreshes that portion) i.e. it displays temperature for
the first 5 secs at 1 to 5, then temp for next 5 secs is also
displayed at 1-5 deleting the old data and so on. The portion of the
graph from 6 - 20 is always kept blank.

I want to set it up so that it displays a new data point as soon as it
gets one. To achieve this, I changed the no. of samples to 1 (from 5
as set above). However, now it displays just 1 point, increasing the x
axis from 0 to 20 doesn't help. How do I set it up so that it displays
a continuous scrolling display like an oscilloscope.

Thanks,
Sumeet.

[kaush]

Hi sumeet,

I guess u r placing chart inside the loop. Please see the attached VI.

[ArchivedPointOnePa]

Sumeet wrote:
> Hi,
> I'm new to labview. I'm facing a very basic problem.
> I need to measure temperature, and I'm using the 9172 chassis and 9217
> module to do that using RTD's. Now, in labview, I added a DAQ
> assistant, and set the samples to continuous with a sampling rate of
> 1Hz. I need to plot this data. However, when I connect a waveform
> chart (strip chart) it displays the data for 5 secs, keeps it stagnant
> for 5 secs, then displays new data after 5 secs and so on. It doesn't
> display it continuously. Also, increasing the X axis from 0 to 20

differences between charts and graphs:
http://www.icon-tech.com.au/faq_frontpanelobjects.html

> doesn't help, it still displays data only in the first 5 secs of the
> graph (and refreshes that portion) i.e. it displays temperature for
> the first 5 secs at 1 to 5, then temp for next 5 secs is also
> displayed at 1-5 deleting the old data and so on. The portion of the
> graph from 6 - 20 is always kept blank.

You'll have to change the buffer size as well.

> I want to set it up so that it displays a new data point as soon as it
> gets one. To achieve this, I changed the no. of samples to 1 (from 5
> as set above). However, now it displays just 1 point, increasing the x
> axis from 0 to 20 doesn't help. How do I set it up so that it displays
> a continuous scrolling display like an oscilloscope.
> Thanks, Sumeet.

See "Real-Time Chart.vi in the Labview Examples