VISA Read buffer size? (Rigol Oscilloscope)

[TimBrown]

I am attempting to read the full internal memory of a Rigol MSO4024 Oscilloscope over a USB cable. I seem to be only able to read the first 4 million data points. I should be able to extract the full 70 million data points for the channel, or whatever memory depth the 'scope is set to.

• I am not timing out.
• Data wise, I get 4,000,012 bytes. The first 12 bytes is just header info. The remaining 4 million bytes correspond to 4 million data points.
• I don't believe this is a 'scope setting issue.
• Attempting to set the I/O buffer size with the corresponding VI just causes an error.
• The Read VISA byte count is set to 500 million
• Using LabVIEW 2017, 32 bit

Any insights into how to retrieve more that the 4 million bytes?

[mcduff]

Try multiple reads in chunks, that is, read the first 1 millions points, then the next 1 million point, etc. I have not used a Rigol, but have done the aforementioned technique with multiple Tek scopes to get 20+ million points.

Basically set the scope to send 70 million points,

Use VISA Read to read the header first and ONLY the header

Make a loop

Use VISA Read to read 1 million *(I8,I16.. ) whatever bytes, (If the raw form of the data is I16 then you need to read 2 miilion bytes for 1 million points) Put into a buffer, DVR, etc

Rinse and Repeat the loop till done.

mcduff