Reduce Sample Number in Streaming Mode

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zipcode
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Joined: Wed Dec 05, 2018 8:54 am

Reduce Sample Number in Streaming Mode

Post by zipcode » Fri Dec 07, 2018 9:40 am

My question is the following: I am running the 4444a in streaming mode and I want a reduce the number of samples , how can be made?
In this case I want 1 sample every 250ms,during a long period of time.

Code: Select all

uint32_t sampleInterval=250
ps4000aRunStreaming(unit->handle, &sampleInterval, PS4000A_MS, preTrigger, postTrigger, autostop, downsampleRatio, ratioMode, buffLength);
..
...
GetStreamingLatestValues(unit->handle, CallBackStreaming, &bufferInfo)
When the callback is made from StreamingLatestValues, the g_sampleCount variable has a value of 64. Is it possible to reduce this number?

zipcode
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Joined: Wed Dec 05, 2018 8:54 am

Re: Reduce Sample Number in Streaming Mode

Post by zipcode » Mon Dec 10, 2018 8:49 am

I'm trying to use ps4000aGettimebase(). With this function i can specify the number of samples and the time interval between readings. Can this be used in streaming mode?
I know that I can specify the time interval between readings when I call ps4000aRunStreaming() but not the number of samples.

Martyn
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Re: Reduce Sample Number in Streaming Mode

Post by Martyn » Mon Dec 10, 2018 1:25 pm

You don't need to use GetTimebase, that is for Block Mode, you specify the sample interval directly in the streaming function together with the time units. sampleInterval will need to be 250, and time units PS4000A_MS, with pre and post trigger samples set to what you need. and with autoStop set to false it will stream indefinitely.
Martyn
Technical Support Manager

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