Sorry if I mistaken anyone w.r.t. digital/analog triggering. Digital/analog triggering is not mentioned explicitly in most descriptions, I made wrong assumption on this.
Siglent HD scopes have digital triggering with many trigger types, but am I missing something here w.r.t. name "digital triggering"? From SDS3000X HD manual, pages 34-35:Trigger coupling: Coupling mode of the current trigger source. It is only valid when the trigger source is C1~C4, EXT, or EXT/5
...
LFR: The signal is coupled through a capacitive high-pass filter network, DC is rejected and low frequencies are attenuated
Does this applies to external trigger only? Is there physical filter for CH1-CH4 trigger?
I consider (full) digital triggering as implemented in scopes like R&S RTO, MXO4/5 where it is possible to set very low (<0.1 div) hysteresis threshold, ADC data stream is crunched to extract trigger events even in high resolution mode, HF reject filter is user tunable, etc.
Do Siglent scopes have some digital triggering specific features as in R&S scopes (i.e. trigger in high resolution mode or change hysteresis to low value)?
You are confusing details of how one manufacturer implemented some functions with a concept of how digital triggering work.
Siglent (and many others) use fully digital triggering.
It is digital because it works in digital domain, on sampled data from ADC.
Analog triggering has physical analog comparator in schematic, that is detecting where edge is.
Some other scopes, like Keysight MSOX3000T/G has hybrid system, where they have analog comparator for Edge trigger but use digital trigger for other types.
Other things R&S implements are just something they implemented in their implementation of full digital triggering.
So your sentence "I consider (full) digital triggering as implemented in scopes..." is not really a thing.
It is like saying "I consider electric car to be fully electric car only if it has 17" multimedia screen like Tesla".
No, fully electric car is any car that has 4 wheels and only electric motor and battery as sole source of motion. Any other equipment is just equipment on fully electric car. It defines features, class, price but not the fact it is fully electric car.