LD2 flashes on Digital Discovery

[Pavel_47]

Hello,

LD2 flashes white on Digital Discovery.

What does it mean ?

Thanks.

[attila]

Hi @Pavel_47

The LD2 on Digital Discovery indicates the following:
- white: logic analyzer is triggered
- blue: auto triggered

[Pavel_47]

Hi Attila,

I've observed two types of behavior on LD2:

• white continuous
• white flashing

Does exist a document where this is specified ?

Thanks.

[attila]

Hi @Pavel_47

The led is lit during logic analyzer triggered state (trig->done) but at minimum of 166ms in order to show short captures too.
It the capture is long or the rate is high the led will stay lit for longer.
The Protocol tool also uses the logic analyzer and its triggering mechanism so it may be lit also when using this tool.
 

[Pavel_47]

I'm not sure that I properly understood your explanation, but indeed there is some relation between LD2 behavior and capture duration.

For example in this example with base 20ms/div (i.e. capture 200ms) and higher, the LD2 flashes; with 10ms/div and lower it's ON continuously

https://i.postimg.cc/zDKn7vDm/Screenshot-from-2020-09-17-13-55-50.png

[attila]

Hi @Pavel_47

The LD2 is lit for at least 166ms for each capture. If the repeated captures are often than this it will stay lit continuously.

With (20ms/div) 200ms capture, having the trigger in middle means 100ms triggered state, so it will stay lit for 166ms and +34ms off, (34ms + delay in trigger + data processing)
With (10ms/div) 100ms capture, it will stay continuously lit if the trigger is arriving it time, <66ms
You should start seeing pulsing with at least 16.7 ms/div