Reading values from input channel in bnc 2110

[Nghtcrwlr]

Hello Dennis

Yes . I have gone through the tutorial . but i need to get used with it to understand everything.Now i got it... But with the timing am not so clear.

Number of samples * Resolution = Duration of measurement in seconds. ( right?)

So if i need 10 samples, how can i measure the data for specific time interval ? and how can i adjust the resolution?

thanks

[NI-Elvis_ForTheWin!]

Hi!

As Mr. Rudolph said before, I'd recommend the LabVIEW DAQ Course as well.

I visited this course too and it was very useful for me. 

I had a lot of questions about DAQ as well, but after the course it was really easy

to handle it 🙂

If you have any questions about how to sign up for this course and so on - I'll help you.

Regards
Melanie Binggeli

[Dennis_Knutson]

No. I don't know where you got that but resolution is the voltage range/2**number of bits.

I think your equation should be number of samples / sample rate. If you specify 1000 samples and specify a rate of 10000 samples/sec, you acquisition will take .1 second.

[Nghtcrwlr]

Hello All

To Dennis:

Yes that was what i wanted. and another thing which i needed was the difference between two sample points. I got it that too..Now my VI is working without any errors. Now i have to get to the second phasee.. thanks guys....

To Melanie Binngeli: Is the tutorial course free or do we have to pay something?

[Nghtcrwlr]

Hello Dennis

I tried with 2 channel input.. see the attachment. WHen i run the VI one of the channel gives output and then shows an error message. When i stop and run the VI again, the other channel gives output. What could be the problem?

Message Edited by Nghtcrwlr on 07-21-2009 02:34 AM

[Melanie Binggeli]

Hi Nghtcrwlr

The course isn't free - but indeed you have a lot of advantages if you visit it,

you'll be able to reduce your costs a lot if you visit this course, because you'll

save a lot of time, which you can use for other projects. 

So in the end I suppose you'll save more money, if you visit the course.

Greetings

Melanie Binggeli

[Dennis_Knutson]

You did the exact opposite of what I said to do. Do NOT use multiple DAQmx Create Channel, DAQmx Start Task, DAQmx Read, etc. You use the example unmodified and just enter multiple channels in the single physical channel controls. You cannot create multiple tasks with a single resource - an analog input. You have a single A/D convert clock and multiple tasks are simply not allowed. Did you think that when I said that 4 VIs was not correct, that using 2 was somehow going to make a difference?

[Nghtcrwlr]

Hello Dennis

Thanks...

Now am able to read values from multiple channels parallely.

 I have another problem.

Lets take an example. I have connected a function generator

to read voltage of a sine signal. When i run the VI i could see the graph data running all the time. I have chosen 100 sample points and the distance between 2 sample points as 0.1 second.
When i stop the VI,the final values collected is shown in the graph. But what i want is , when i say 100 samples, the VI should read data values of only those 100 sample points and then stop. How is this possible?

Message Edited by Nghtcrwlr on 07-23-2009 04:23 AM

[Dennis_Knutson]

If you want finite samples then don't specify continuous sampling and don't use a while loop. Just do a single DAQmx Read with the sample rate and number of samples that you want.

[Nghtcrwlr]

Thanks Dennis!!! I was using continous samples. Now after removing while loop , its wrking. I have started a new measurement for 24 hrs long. hope it will wrk without errorss...:D

Message Edited by Nghtcrwlr on 07-24-2009 01:27 PM