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picoscope 3404B start phase

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picoscope 3404B start phase

Postby Nicola_1987 » Tue Nov 20, 2012 3:09 pm

Hi

I try to use the example "PICOSCOPE3000aExampleStreaming" for work with the picoscope 3404B but a lots of time, when I run the programe, sometimes

start the programe then if I stop and restart give the error

PICO_not found.

I do not why, and sometimes is green the light but often red.

I used the driver

ps3000a.dll

is it ok

thanks

Nicola
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Re: picoscope 3404B start phase

Postby Hitesh » Tue Nov 20, 2012 4:23 pm

Hi Nicola,

Which version of the PicoScope 3000a SDK are you using? Please ensure that you have the latest SDK which you can download from http://www.picotech.com/software.html

In Step 1, select the PicoScope 3404B, and in step 2, select the option for the Software Development Kit.

One thing you may wish to do is add a library function call to ps3000aStop in the outer loop - this function stops the device collecting data.

Does the device work ok with the PicoScope 6 software?

Regards,
Hitesh

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Re: picoscope 3404B start phase

Postby Nicola_1987 » Tue Nov 20, 2012 4:47 pm

THANKS

now work,

but is it possible made initialization of the picoscope more fast , because after the program is start, is it necessary 3-4 second for the initialise of the picoscope.


Another question :

when I use Picoscope3000aExampleStreaming.vi, the default execise is only Channel A,
but in the block P3000 setting is possible to enable 4 channel, but in the block there is only one connector so is it necessary to modificate?

because if I will put enable in channel B, the programme give an Pico_hand error

thanks

Nicola
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Re: picoscope 3404B start phase

Postby Hitesh » Wed Nov 21, 2012 12:50 pm

Hi Nicola,

Are you referring to the initialisation when running LabVIEW? This is because the driver is establishing a connection to the device and updating the firmware.

For two channels, you need to modify the vi file to output the data values for Channel B as well. The examples are provided to demonstrate how to call the dll functions.

I hope this helps.
Hitesh

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Re: picoscope 3404B start phase

Postby Nicola_1987 » Fri Dec 07, 2012 9:45 am

Dear

I try with control to view two channels, and save in txt file the value of the waveform shape during the acquisition.

I need to acquired the waveform in a interval of time correct.

Actually one parameter is the number of sampling, but is express in ms , I think to default, if I want the time stamp in the

graph, not the sampling, usually is the inverse of time sampling, or not?

I attached the two different program that I modificate from the example streaming.

I hope someone can help me

regards

Nicola
Attachments
a_4_12.vi
save the waveform with the inverse of sampling
(25.3 KiB) Downloaded 123 times
a_save_4_12.vi
save waveform with the sampling
(32.11 KiB) Downloaded 124 times
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Re: picoscope 3404B start phase

Postby Hitesh » Fri Dec 07, 2012 10:08 am

Hi Nicola,

If you know the sampling interval e.g. 1ms, then on the time axis you should be able to use the formula

time at sample = sample interval x (sample number - 1)

The '-1' offsets for time 0.

I hope this helps.
Hitesh

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Re: picoscope 3404B start phase

Postby Nicola_1987 » Fri Dec 07, 2012 10:31 am

Hi

thanks

in this case I did this modification in my software , but I am not sure if is correct or note,

the problem of this program the interval of sample is not change during the test how can I make .


because I have dynamometer and the output I acquired with the picoscope, and I need capture the waveform in determinate interval of time
Attachments
a_7_12.vi
(25.44 KiB) Downloaded 115 times
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Re: picoscope 3404B start phase

Postby Hitesh » Fri Dec 07, 2012 11:18 am

Hi Nicola,

I've run a quick test of your vi and there is an issue in your time calculation.

What sampling interval do you require?
How long do you need to capture data for?

Once the sample interval has been set for a run it cannot be changed.

Regards,
Hitesh

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Re: picoscope 3404B start phase

Postby Nicola_1987 » Fri Dec 07, 2012 11:24 am

the problem in each test change and usually I need to impose during the test , is not possible to fix in real time , and change this


Nicola
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Re: picoscope 3404B start phase

Postby Nicola_1987 » Fri Dec 07, 2012 11:37 am

Hi

for example I try with this other way to fix the time sample in real time , but not work very well


Nicola
Attachments
a_7_12_modificate.vi
(26.65 KiB) Downloaded 118 times
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Re: picoscope 3404B start phase

Postby Nicola_1987 » Fri Dec 07, 2012 11:44 am

Hi

usually the time 0.029 ms of more but change in each test,

there is some way to change during the test ?


Nicola
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Re: picoscope 3404B start phase

Postby Hitesh » Fri Dec 07, 2012 11:54 am

Hi Nicola,

To confirm - are you using a sampling interval of 29 microseconds? How long do you need to capture data for? How many samples?

I think you may want to consider using a block mode capture with a trigger enabled. Here it will only capture the number of samples (pre-trigger plus post-trigger) that you tell it to.

I hope this helps.
Hitesh

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Re: picoscope 3404B start phase

Postby Nicola_1987 » Fri Dec 07, 2012 12:02 pm

Hi
I think i need to capture every 0.029 ms , for length time less than 0.029 ms

I do not undestand using a block capture, there is some example.

Because I think the streaming in real time its ok, then the stream real time waveform I need to save in txt file,

Can you help me ?

So do You think start to the basic program that I had is wrong ?

Nicola
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Re: picoscope 3404B start phase

Postby Hitesh » Fri Dec 07, 2012 12:09 pm

Hi Nicola,

I will contact you through our e-mail Helpdesk.

Thanks.
Hitesh

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Re: picoscope 3404B start phase

Postby Nicola_1987 » Tue Dec 18, 2012 11:12 am

Hi


in the streaming program the value of the amplitude of the signal, what is represent, which is the relation with the VOLT, if I impose 1 V of range of the signal


thanks

Nicola
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