Drawing a temperature waveform using USB 9211A

[Andy Tung]

Deu to I'm new to LabView, so I want to ask a "easy" question.

Now, I'm developing a application using USB series DAQ devices. And it's successful to get the value of temperature from USB 9211A.

I'm drawing a waveform chart from values. There are some questions I want someone who can help me to solve them.

1. I want my waves are displayed in "sine" type. Because my waves are displayed in a strange type(is a square shape).

2. How to make the time is "fixed"? I just want display it in 60 seconds all the time. So I need the time is just from 0 to 60.

3. How to initialize the time of waveform? (Not accumulated)

Hope there is someone who can help me to solve the above questions. Thanks a lot.

Andy

[Dennis_Knutson]

I'm not sure what you mean by "sine type" or "square shape". The only thing that comes to mind is that you've got bar plots selected or the interpolation. In the plot legend, right click and you can change these items. If that's not it, post your VI or a picture (no bmp please) of what you're seeing. For help on clearing a chart, look at the shipping example "How to Clear Charts & Graphs". Probably all you need to do to limit the chart to 60 data points is to turn of the x autoscaling. You can also set the chart history to only 60 points. You might also want to look at the shipping example called "Real-Time Chart".

[Andy Tung]

Dennis Knutson,

Thanks for your advices. The third question I had is already solved. Now I appended 3 files which included the image of waveform(waveform.JPG), my application file(TempRead.vi) and the data of waveform(data.txt).

Please check them for helping me.

My developement platform:

Windows XP SP1, LabView 7.1 Developement, USB series DAQ devices(9211a for temperature reading)

Thanks a lot.

God bless you.

Andy

[Andy Tung]

Hello,Dennis Knutson:
  Question 1 and 3 I had solved already. Thanks for your helping. But now, I have a very strange situation on temperature measurement using USB 9211A. I'm making a short description here. And please help me to figure out.
  I have two applications which contain the same module inside there. There is the question I meet, the same waveform module generate two kinds of chart in two vi files. This is a strange situation I mentioned. Now I attached files of vi and images of waveform from these two applications. Please help me to find out where the problem is. Thanks a lot.

God bless you.

[Dennis_Knutson]

Your pictures seem to indicate you still have problems with question 1 and not 2. I think your problem might be that you have the Transpose Array selected for the chart.

[Andy Tung]

Dennis:

  Thanks for your answers. It works out. But I have another question. How can I make the "Time"(X axis) of waveform chart synchronous with the time I setup.

For example, I have a temperature waveform to display a data(plot) in each second. I want my waveform chart display synchronously with the time which its unit is "second". Can you tell and answer for me how I could reach to it?

Thanks a lot.

Andy

[Dennis_Knutson]

Look at the shipping example called Real-Time Chart.

[Andy Tung]

Thanks for your helping, Dennis!