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Products => Test Equipment => Topic started by: markv6 on November 23, 2018, 01:58:02 pm

Title: Hantek DSO5102P sampling frequention
Post by: markv6 on November 23, 2018, 01:58:02 pm

My processor generates a burst of 10khz. When measuring this pulse with the DSO5102 it shows a low frequency random pulse. After a hour searching why outputting a simple pwm does not work see here:
(https://lh3.googleusercontent.com/-Yze1dx81Oto/W_gFIvHQRGI/AAAAAAAADzs/LO7wJ5VKfOcayr1BoGeDdpoxvNJaVkt8ACJoC/w530-h318-n-rw/pic_3_2.bmp)

Problem is the sample frequency of the scope is exactly my pwm frequency so it does not show the pulse. Changing the timebase:
(https://lh3.googleusercontent.com/-ZclRB77Wt6c/W_gFEt3eCUI/AAAAAAAADzs/v5KLuuxoCdssa6w1xmq35nOXXckX3-S-gCJoC/w530-h318-n-rw/pic_3_1.bmp)

When changing the pwm frequency to 21khz the picture is as aspected:

(https://lh3.googleusercontent.com/-xP8HizBQDaU/W_gGlnXxtHI/AAAAAAAAD0I/LoWA2zCibLIC0704UQ56x6CU0vOswdx8gCL0BGAs/w530-d-h318-n-rw/pic_3_3.bmp)

I have used serval digital scopes, Agilent Tektronix Rigol but never had this problem. It is worthless if you cannot thrust what you see.

Title: Re: Hantek DSO5102P sampling frequention
Post by: tautech on November 23, 2018, 06:54:24 pm

Try adjusting trigger holdoff to 20+ ms.

Title: Re: Hantek DSO5102P sampling frequention
Post by: paul on November 23, 2018, 08:55:20 pm

This is normal, I have fallen into the same trap with a Tektronix scope.
Use the Peak mode on the Acquire menu, this will increase the sample rate and catch a lot of the higher frequency stuff / glitches you just cant see in the “Normal” acquire mode,  or up the memory depth (this doesn’t always increase the sample rate and can slow the scope down a bit).

Paul.