Discovery 2/ADP3450 Scope/Logic synchronized record with different sampling rates

[A_Beta]

Hello,

My application needs a synchronous sampling of logical inputs and analog inputs at the same time.

I need to sample two differential analog inputs with 1 MS/s and 3 to 4 digital inputs with at least 8 MS/s (SPI at 3.5 to 4 MHz with MISO only). I need to sample at least 250 ms, up to 500 ms.

It is possible to synchronize the digital inputs to the analog inputs ? I need to timestamp of the CS from the SPI synchronized to the analog input data.
If I want to record data with the scope/logic, the sampling rate is limited to 1 MSPs on the Discovery 2 and up to 4 MSPs on the ADP3450 if I use WaveForms3.

Is it possible to use the WaveForms API together with Python (or something else) to implement this synchronous readout, possibly with different sampling rates to save needed MPSs on either Discovery 2 or ADP3450?

 

 

Edited April 8, 2022 by A_Beta

[attila]

Hi @A_Beta

AD2 and ADP3 can capture up to 100/125MHz. The Scope can be used in mixed mode by adding Digital channels.
The AD2 can record/stream up to around 1MHz. Depending on computer and available USB bandwidth.
The ADP3 in standard can record up to 128MiS@500MBps, for 2 Scope and digital channels about ~40MHz rate, for 4+digital ~20MHz.
The digital bandwidth usage with data compression depends on signal activity rate.

As a last minute change, in the latest version the digital rate/samples adjustment is enabled for recording but it is still automatically set to analog values if these are changes. So adjust digital rate/samples under Options every time before starting a record and make sure it is not longer than the analog time. I'll try to optimize this in the next versions.

[A_Beta]

Hi @attila

I will try it out with the AD2 beginning next week. I have it with me currently. I will see about getting the AD3.

Thank you very much.

[attila]

Hi @A_Beta

The latest version adds separate option for digital rate/samples:

[A_Beta]

Hi @attila,

 

I'm currently testing it with the AD2 and the newest beta version 3.18.29. The data recording takes a really long time. What exactly happens during the recording in this case. Is the digital buffer too low?

I have the current settings:

 

Device Manager Settings set to 8. 

 

Additionally, i get the message about lost samples in the digital scope. To set the settings in the device manager to the 4th configuration.

 

I think I might need the AD3 for my setup to work.

 

You really need either more device buffer or USB 3 for your next Measurement device. With hopefully good enough ADCs (resolution).