Test and Measurement Forum

data streaming with pico 5444B

Post your LabVIEW discussions here

data streaming with pico 5444B

Postby Rob_T » Tue Jan 21, 2014 8:38 pm

Hello!

We have a Pico 5444B. We need to acquire simultaneously 4 signals, sampled at least at 1MHz per channel for a total acquisition time of 5 minutes, more or less.

If I'm not mistaking, we cannot do it with the Picoscope 6 software. Therefore I'm trying to use Labview.

1) First of all, in your opinion, is it possible to do it ?
We need also to be very accurate during the acquisition: It would be very useful to see in a graph the signals during the acquisition but we need a stable system, able to acquire costantly at least at 1MHz for all the acquisition time.

2) In order to become a bit more confident with the topic, I have downloaded and start to use the good SDK for this Pico model:

PS5000Asdk_r10_5_0_28

I've looked around in several examples and at the moment I'm working with the VI attached.
It can acquire a signal in streaming, with a maximum sampling interval of 1 microsecond, plot it in a graph and save it.

I have some questions:
(I hope I'm not mistaking, otherwise please correct me. I'm also a beginner with Labview)

- I should be able to increase the sampling frequency (Fs) up to around 7 Mega per channel, acquiring at 8 bit and 4 channels. How?
- I cannot acquire for long time at high frequency.
I tried to extend the "Overview Buffer Size" to the correct number of samples for an acquisition of 100 seconds at Fs 1MHz. It isn't working. I guess is a setting problem. Maybe I'm using the internal buffer, the ram, I don't know. Is it possible to pass this limit?
Finally, related to plot and save the data:
-Is it possible to save the signal as '.mat' file like in picoscope6?
-When I'm calling the GetStreamData function to upgrade the plot, is it the pico still acquiring or the streaming is interrupted? It Is fundamental for us to have a continuous acquisition, at high frequency, without interruption.

Thanks in advance for the support!
Roberto
Attachments
PICO_streaming.vi
(33.93 KiB) Downloaded 132 times
Rob_T
Newbie
 
Posts: 0
Joined: Tue Jan 21, 2014 9:22 am

Re: data streaming with pico 5444B

Postby Hitesh » Mon Jan 27, 2014 6:02 pm

Hi Roberto,

Are you looking to process the data in MATLAB? If so, you may wish to consider using the Instrument Control Toolbox driver. There might be 3rd party vi's available to save LabVIEW data to a .mat file.

With PicoScope 6, you could stream for a duration of 200 or 500 seconds - for 5 minutes (300 seconds) you could set a trigger point at 40% and discard the first 200 seconds of data.

It should be possible to stream at approximately 7MS/s with 4 channels.

The overview buffer is a temporary buffer from which you should copy the data into an application buffer - the wrapper dll can do this if you call the functions to set the driver and application buffer.

Streaming will not be interrupted when retrieving data via the GetStreamingLatestValues function.

There is a LabVIEW streaming example under test for the PicoScope 5000 series which ensures data is copied correctly using the wrapper dll. If you would like to test this or have the MATLAB Instrument Control Toolbox and wish to test the MATLAB streaming example, please e-mail support@picotech.com

Regards,
Hitesh

Technical Specialist
Pico Technology
Hitesh
Site Admin
Site Admin
 
Posts: 2063
Joined: Tue May 31, 2011 3:43 pm
Location: St. Neots, Cambridgeshire


Return to LabVIEW

Who is online

Users browsing this forum: No registered users and 0 guests