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Arbitrary waveform generator issue

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Arbitrary waveform generator issue

Postby atulkumar » Tue Jan 10, 2012 11:06 am

Hello!

I am using a 2205 device and want to use the AWG to produce a wave. With a fixed waveform, it works fine as I call the ps2000_set_sig_gen_arbitrary function once with some values and the waveform is produced as expected. But if my program wants to change the data in the buffer (to change the waveform at runtime), I need to call the ps2000_set_sig_gen_arbitrary function again (because to the best of my knowledge the driver API does not provide any function to directly change the values in the device buffer that is used for AWG). The problem is that when the ps2000_set_sig_gen_arbitrary function is called, a random spike is generated by the device for a short time. If the ps2000_set_sig_gen_arbitrary function is called fast enough (even as slow as once every two seconds), the spike is clearly visible with the waveform. So the signal cannot be used for any meaningful purpose. Is there a way to get rid of the spike that is caused by a call to the ps2000_set_sig_gen_arbitrary. If not then is there a way to directly change the values in the device buffer?

Thanks,
Atul
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Re: Arbitrary waveform generator issue

Postby Martyn » Tue Jan 10, 2012 1:02 pm

When calling the ps2000_set_sig_gen_arbitrary function it stops and starts the scope which is why you are seeing the spikes. Unfortunately it is not possible to change the waveform on the fly due to the way in which the hardware operates.

If you wish to discuss this in more detail then please contact the support team at support@picotech.com
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Re: Arbitrary waveform generator issue

Postby atulkumar » Wed Jan 11, 2012 8:42 am

Thanks Martyn for your reply. I'll write to support@picotech.com.

But I dont think its the hardware limitation. Because when I use Picoscope 6 software's Signal Generator interface and then change some signal properties while the signal is being produced and viewed on a dedicated Oscilloscope, I dont see any spike in the waveform. Does Picoscope 6 also used the same API? I doubt.

Regards,
Atul
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Re: Arbitrary waveform generator issue

Postby Martyn » Wed Jan 11, 2012 9:27 am

Picoscope 6 does use the same API and I have seen this effect particularly when using a low signal generator frequency and then changing the wave type.
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