time base and samples

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mmajo
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Joined: Thu Nov 01, 2012 1:37 pm

time base and samples

Post by mmajo » Thu Nov 01, 2012 2:20 pm

Hi,

I have a rather simple question related to settings in the block mode. I use a picoscope 3204a and want to sample with a sample rate of 1.9MHz. I set the time base to 8, which should give me 500 MS/s /2^8 = approx. 1.9MS/s. I guess I now have a sample rate of 1.9MHz.

Then I set the PreTriggerSamples to 0 and the PostTriggerSamples to 1000000. How does this affect my samling rate? Does it mean that I then sample at 1.9MS/s /0.5s = 3.8MHz?

Thanks in advance

Hitesh
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Re: time base and samples

Post by Hitesh » Thu Nov 01, 2012 4:51 pm

Hi,

For sample intervals above 8ns, the following formula is given in the Programmer's Guide:

Code: Select all

sample_interval = (timebase - 2) / 62500000
A sample rate of 1.9MS/s would corresponds to a timebase of 35 (528ns).

The number of samples that you specify in call to the RunBlock function will not affect the sampling rate. Multiplying the sample interval and number of samples should give you the time period in which the samples are taken - this should give you around 0.526 seconds.

I hope this helps.
Hitesh

Technical Support Engineer

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