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Continuous Logging using the ADC 216

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Continuous Logging using the ADC 216

Postby Guest » Fri Feb 18, 2005 1:31 pm

I have a requirement to perform continuous logging of a high resolution (16 bit or better) sampled audio signal. The signal bandwidth is low, my sample rate will be 500 Hz, and I will need to sample 2 channels.

The ADC 216 looks like the right part for this application. Does it support continuous logging? I don't mind writing my own software to control the unit and collect the data (since your logging software appears to be limited to 1 Meg samples). But it must be able to run for many hours without dropped data.

Please advise...
Guest
 

Postby Sarah » Mon Feb 21, 2005 9:41 am

Hi

Thank youfor your post.

You could use the ADC-216 over a long period of time for sampling, however because of the block method it uses to aquire data the would be small drops in data.

This is because the unit gathers data into the buffer before downloading it to the PC, then when it downloads the data it has to pause the sampling. The gaps in data would be small, but we cannot unfortunately give continual recording with the unit in the way that you require.

Hope this helps

Best Regards
Sarah
 

Postby marcoz » Wed Mar 16, 2005 9:02 am

Hi Sarah,
Can your 3000 or other picoscope series support continual recording?

cheers

Marcoz
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Postby Sarah » Wed Mar 16, 2005 10:04 am

Hi

Thank you for your post.

The PS3000 series can stream data at lower sampling rates, thus enabling continuous sampling. This will however only be possible at slower sampling speeds.

Hope this helps

Best Regards
Sarah
 

Postby Guest » Wed Mar 16, 2005 8:29 pm

Hi Sarah,
what is the maxium continous sampling speed for the 3000 series?

cheers

Marcoz
Guest
 

Postby Sarah » Thu Mar 17, 2005 11:56 am

Hi

Thank you for your post.

The maximum sampling speed for streaming on a PS3000 is 1kHz each channel.

Hope this helps

Best Regards
Sarah
 

Postby puposet » Fri Mar 25, 2005 5:35 pm

I've been studying this sort of problem for looking at intermittent faults in industrial position controls.

In my case what I need is to be able to record at least two channels of +/-10v analogue data at around 10ksps to at least 8bit resolution with a reference ground which will be within measurement range of true ground but not connected directly to it for EMI reasons. A channel or two of 24V digital data alongside would be a bonus. I would then want to record continuously without gaps and retro-capture perhaps a minute's data after an event occurred and an operator pressed a key or closed a switch.

This is the sort of thing that would seem to fall within the general scope of Pico equipment, but there does not seem to be anything that will do it, even if I build my own input signal conditioners. It is perfectly within the capabilities of Pico hardware to achieve realtime rates of 10ksps or higher, eg using unbuffered real time sampling under hardware timing and DMA transfer (like a photo scanner does) but the Pico software drivers do not seem to extend to this.

To the original post:
Dear Guest, if you are prepared to write your own software, then you most likely already have a piece of hardware that will do exactly what you want - your sound card. You just need to write some Windows Multimedia C code to grab incoming audio buffers, reduce the sampling rate by throwing away (or summing) 15 out of every 16 values, and store them. Not rocket science.
Tim Jackson
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