Oscilloscope

[<0>]

I have two problems:

First:

I was trying to do V/div Control for Agilent MSO6104A(4 Channels). This control changes the vertical sensitivity (i.e. gain) of the oscilloscope.  I was refering to Two Channel Oscilloscope.vi (NI examples). Two channles share the same V/div control, but it was not what I want. I need each input channel to have its own independent V/div control. I tried to plot each channel then use "Bulid Array" to combine the entire waveform graph. But the scaling was wrong when I combined individual grahps into one graph. I also tried using duplicate scale function for the waveform graph, and make each channel refer to different Y-scales. Unfortunately, the scaling was wrong when combined together.

Currently I am using waveform graph to plot waveform. Am I using the wrong plot method? Or is there any other way? Someone can help me? Hope I have made myself clear.

Second:

Since I'm using Agilent MSO6104A, I need to collect data from all 4 channels in real-time. I tried to save the data from all 4 channles at once, but when I plot the data, some waveforms are not correct (please refer to attached files). I'm not sure if it is due to the different scaling of different waveforms. But when I tried to save the waveforms one by one, the waveforms are quite ok and resemble sine(cosine) waveform. However, saving one by one doesn't give me the data of all 4 waveforms at the same point of time.  So I tried to write my VI to read 4 channels in parallel instead of sequential, and it was not working. Please kindly give some advice. Really appreciate that.

Thanks for the time~~~

Thanks for the time~~~

[<0>]

Attached Files~~~

Message Edited by <0> on 08-21-2008 12:11 PM

[Eli_S]

Hi,

Please take a look at the VI I am posting here. I am simulating two signals and ploting them on a Waveform Graph. I have created two different scales and set each plot to use a different scale in the Properties of the Waveform Graph.

The VI is saved in LabVIEW 8.5, let me know if you have any problems opening it.

[&lt;0&gt;]

Hi Eli_S,

Sorry that my LabVIEW is version 8.0. Could you save it as previous version?

Thank you so much~~~

[Eli_S]

Sure! Here it is.

[&lt;0&gt;]

Hi Eli s

Thank you!

I note that you put different Yscale ranges for CHA and CHB. Can you explain why you put scaling in that way?

[Eli_S]

I believe you mentioned you want each channel to have its own control for V/div. If both controls use the same scale then you are defeating the point of having one control per channel. I created to scales, one for each channel, so that each control modifies the corresponding scale.

[Kurting]

Hi Eli_S,

I think i encounter the same problem. I used ur idea of 2 channels scope sample to extend to 4 channels, but it was not working.

Could you kindly give some suggestion on how to do it for the 4 channels?

Many thanks!

[Chongnang]

Hi,

Is it OK to put the signal in 2 waveform graphs?

When using the active scale and range property node, I found that there are only 2 plots that can change the Y-scale. If you can use 2 waveform graphs, One is to acquire signal 1&2 and another is to acquire signal 3&4, it would be easier to set the scale.

Please see the attached VI. Hope this help a bit.

Gunyapart Deephanphongs

Application Engineer

NI ASEAN