Digital Discovery - trigger on bus value

[Belargo]

To familiarize myself with the new device I went through the "Get Started" tutorial for Digital Discovery.

I'm not sure how should I interpret the results of setting up trigger on the bus state (value). The tutorial sets up the pattern generator using 4-bit binary counter and the outputs are physically looped back to digital inputs of the logic analyzer. It's a "generic" bus with 4 data lines.

To test triggering I tried setting up different triggers using "Simple" and "Pulse" trigger modes. They seem to work as expected.

However, I'm not sure what to think about the "Protocol" trigger mode:

• When selected it displays "Bus" (generic bus which is OK)
• Selecting "Bus" it opens "Bus Trigger" dialog box (OK)
• In the "Trigger" drop down field one can select five preselected values only and cannot manually enter any other value (?).
• After running in "Single" mode with one of the preselected values - the LA triggers, but trigger mark doesn't point exactly to preselected bus value.

1. Does the above mean one cannot specify his/her own bus value for the trigger (there are 11 counter states which are not listed in the "Bus Trigger" drop down list.
2. What does it mean that if "Trigger" is set to e.g. 7 and after acquisition the trigger marker points to value 5? (do I interpret correctly the small black triangle at the bottom being trigger point?).

Any information regarding the above will be appreciated. Possibly being new to the device and software I neglected to set up something somewhere correctly, but I followed instructions in the "Get Started" step by step.

[attila]

Hi @Belargo

Corrected to be editable in newer version:

[Belargo]

Thanks for the information, Attila.