Siglent SDS1104X-E oscilloscope - mystifying trigger

[frank2644]

The attached display trigger is mystifying to me. The "single" trigger is set for rising on channel 1 and yet it sometimes triggers almost randomly, or near the channel 2 signal as in attachment 1. The bottom half of the display is zoomed in-case there was a very short trigger but none is shown. On the same scope settings sometimes I get a good display showing the expected trigger signal(attachment 2). Again, many times the trigger signal is missing on the display as in attachment 1.

I'm trying to develop Arduino rotary encoder logic and not making much progress.

I'm kinda new to digital scopes so hopefully I'm missing something simple.

Any suggestions are welcome..
Frank

[tautech]

Try using a factory Default just in case some other mode/setting previously used is still active.

Another thing to consider is when using 2 channels and the sampling rate has dropped (top right near the frequency counter) is to instead use one of the channels on ch3 or 4 to have them on the 2nd ADC and maintain both higher sampling rates and also use the memory of the 2nd ADC.

BTW the easiest way to grab and present screenshots is capturing them to USB with the blue Print button.

[Performa01]

Make sure you're using "Normal" Trigger, not "Auto".

[frank2644]

Thank you everyone for the replies, I think it's working better after resetting to default. I'm still getting mystifying triggers, but now when I zoom in I can see very short ringing spikes that is causing the trigger. I couldn't see those spikes prior to resetting to default. I suppose it could be user error (me) but I did look for those spikes previously and could not find any...

In any case, I'm much happier now, thanks to all again.

Frank

P.S.
1. I'm using a web browser and screen capture to make the jpg's. Probably the USB technique produces better quality JPGs, I'll
have to try it out.
2. I  didn't use auto, I was using a single trigger, However, the suggestion to use normal is even more convenient because I don't have to rearm the trigger for each test.

[tautech]

Print sends a PNG screenshot to USB and they are small in size normally ~50kb.
It's really a convenience shortcut rather than need to dive into the Save/Recall menu where you can get a # of different screenshot formats.

You can also set your own preferred Default setup with these scopes in the Save/Recall menu however it's best to do a Factory Default first then set the scope as you'd prefer to have it set and then save it. Then the Default key will be your own personalized setup yet it's simple to return to the Factory Default.

[Performa01]

You can get the same high quality screenshots from the web interface if you use the "Screen Save" button (the leftmost orange one).

This will capture a screen shot, but instead of storing it on an USB stick, it will transfer it to your PC and store it in your default download folder.