Dropout gaps in streaming samples by console application

Post your C and C++ discussions here
Post Reply
thsc
Newbie
Posts: 0
Joined: Wed Jan 18, 2017 6:56 am

Dropout gaps in streaming samples by console application

Post by thsc »

Hello,
I build a console application for a 6404D picoscope to sample data to my pc disk.
For first tests I took 1 million samples but sometimes the collected data has some dropout gaps in the curve. I build the console application by the Eclipse Cpp Neon IDE with the code Pico supported. My further target is to collect data for a time of 20 seconds at a sample rate of 50 MSPS.
During different test I found out that Picoscope did an auto stop before reaching the given number of samples to stop the streaming.
Is there a known topic in the hardware or did I make an error with my buffer handling?

I attached pictures of the signal curve O.K. and NotO.K. and also the c-code I used to build the application.
signal not ok
signal not ok
signal ok
signal ok
ps6000con.c
c code for console application
(73.73 KiB) Downloaded 525 times

Best regards

Thomas Schaefer
NDT Global

Hitesh

Re: Dropout gaps in streaming samples by console application

Post by Hitesh »

Hi Thomas,

Which version of the ps6000.dll are you using?

Is the device connected to a USB 2.0 port or USB 3.0 port?

The overview buffer size of 20e6 looks quite large - try reducing this value to something like 1 to 5 MS. This buffer only needs to be slightly larger than the time it takes to execute each iteration of the loop.

When you refer to a problem with the auto stop, how many samples are being collected up to the point where the auto stop flag is set in the callback?

Regards,

thsc
Newbie
Posts: 0
Joined: Wed Jan 18, 2017 6:56 am

Re: Dropout gaps in streaming samples by console application

Post by thsc »

Hello Hitesh,

thank you for your hint's.

Here are some information to my setup:
- The Version of my SDK is 10.6.10.22
- The device is connected via UBB3.0
- In case of auto stop the number of samples is sometimes 0 and often between 100k to 400k samples

I tried to reduce the buffer size but this does not eliminate the problem.

Which size of post trigger samples will be useful for manually stopped streaming over a time of circa 20 seconds?

Best regards

Thomas Schaefer

Hitesh

Re: Dropout gaps in streaming samples by console application

Post by Hitesh »

Hi Thomas,

Try testing the application using the ps6000.dll and picoipp.dll files from the PicoScope 6.12.5 installation directory as they are more recent. These are 32-bit drivers, so if you require 64-bit versions, please respond on your existing support ticket and I can make them available for download.

Regards,

Post Reply