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Entry  Sun Mar 6 17:54:47 2022, Matias Senger, Why does not trigger at higher sampling frequencies? 
    Reply  Mon Mar 7 08:45:32 2022, Stefan Ritt, Why does not trigger at higher sampling frequencies? 
       Reply  Tue Mar 8 00:25:56 2022, Matias Senger, Why does not trigger at higher sampling frequencies? 
          Reply  Tue Mar 8 12:20:00 2022, Matias Senger, Why does not trigger at higher sampling frequencies? 
Message ID: 871     Entry time: Sun Mar 6 17:54:47 2022     Reply to this: 872
Author: Matias Senger 
Subject: Why does not trigger at higher sampling frequencies? 

I have connected 3 signals to the DRS4 Evaluation Board V5 which look like this in the drsosc app:

Note that here I am sampling at 5 GS/s. Using this app everything works perfect.

Now I want to repeat this using the C++ API (which I am actually wrapping to use within Python, see here if interested https://github.com/SengerM/pydrs ) but can only make this to work at lower sampling frequencies up to 3.9 GS/s. This is how I am configuring the board followint the `drs_exam.cpp` file:

```python
board.set_sampling_frequency(Hz=SAMPLING_FREQ)
board.set_transparent_mode('on')
board.set_input_range(center=0)
board.enable_trigger(True,False) # Don't know what this line does, it was in the example `drs_exam.cpp`.
board.set_trigger_source('ch4')
board.set_trigger_level(volts=-.1)
board.set_trigger_polarity(edge='falling')
board.set_trigger_delay(seconds=TRIGGER_DELAY)

```

The full code is here https://github.com/SengerM/pydrs/blob/master/tests/test_drs.py but anyway, my previous snippet can be considered as pseudo-code and if more details needed I can provide.

This is what I get as I increase the sampling frequency:

Up to 3.95 GS/s it works perfectly. At >= 4 GS/s it just never triggers. A few times I was able to make this work at 4 and 5 GS/s playing with the trigger delay, but this seemed to be some kind of random luck because I was not able to replicate it even with the same values.

Any help is appreciated.

Best,
Matías.

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