Pico Technical Support and Discussion Forum

folkertdejong · User Joined: 01 Aug 2007 Posts: 2

Does the ADC-11 have a memory buffer for burst measurements or is it actually a stream measurement? Is there a limit to the number of samples?

The ADC-11 is delivered with picoscope software. Does that mean that it also fucntions as a scope?

thanks,

Folkert

picojohn · Site Admin Joined: 11 Jun 2007 Posts: 391

Hi folkertdejong,

The ADC-11 does not have buffer memory for 'fast block' mode, however, the sampling interval is fixed by the the logger. In this way, effective behaviour is 'fast block' even though actual operation is 'streaming'.

The maximum number of samples in a single run is 1 million, however, the number of runs are not limited.

The ADC-11 can function as a four channel oscilloscope in which any of the 11 channels may be selected.

Regards
John

folkertdejong · User Joined: 01 Aug 2007 Posts: 2

Hi John,

thanks for your answer.
Two more questions to be sure:

What I actually want to do is measure for 3-4 seconds (i.e. without interruption) with a sampling rate of about 10kS per second.
According to your information, this should be no problem. Correct?

With regard to the scope. Suppose I would use one channel, what would be the maximum frequency I could measure.

Thanks again and best wishes,

Folkert

picojohn · Site Admin Joined: 11 Jun 2007 Posts: 391

Hi folkertdejong,

The maximum sampling rate possible with the USB ADC-11 is 20 ksps (15 Ksps parallel ADC-11), however, that is divided by the number of active channels.

Also, the ADC-11 and the PC both have performance limits and will rarely be able to give exactly the settings that are requested. In block mode, PicoLog will attempt to negotiate the requested settings based upon one of two user options:

a) The total collection time remains constant - Here, the time will remain very similar to that requested and the number of samples will be compromised.

b) Number of samples remain constant - Here, the number of samples will remain very similar to that requested and the collection time will be compromised.

In practice, you could prioritise the collection time for 3-4 seconds and PicoLog will collect the best number of samples possible in that time. Alternatively, you might prioritise the number of samples required and PicoLog will collect those in the best possible time.

In single channel Scope mode, you could typically expect to measure up to around 7KHz, (sine wave assumed) though the displayed waveform would be poor, or, around 1.5KHz with reasonable sine shape.

Regards
John

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