Hi,
For general information I noticed an undocumented feature in the DSO154Pro.
Since the feature is not covered in the documentation, it may be firmware/hardware dependant and not fully tested.
Whilst in the “Disp” Menu, press the “Stop” button.

Two options are available “F_Meter” and “Counter” as shown below.
Note: The options are mutually exclusive.

Enable the “F_Meter” by moving to the “ON” icon and pressing the “OK” button.

The “F_Meter” works irrespective of the time-base setting as shown below, unlike the normal frequency reading used in “Meas” options which is based on the waveform shown on the screen.

Notes
- The “F_Meter” seems to use its own auto trigger level setting, irrespective of the setting in the trigger menu.
- The “F_Meter” reading is updated whilst in run mode and keeps the previous value when the “Stop” button is pressed.
- The “F_Meter” seems to work correctly from around 30Hz up to 12.5MHz. The resolution is much better than the normal frequency reading used in “Meas” options.
Below 30Hz the reading is erratic, perhaps due to the auto threshold detection.
Above 12.5MHz the reading does not seem to be valid.
- The “F_Meter” will not operate correctly if the oscilloscope voltage range is set to high.
Enable the “Counter” by moving to the “ON” and pressing the “OK” button.

Notes
- The “Counter” seems to count the number of rising edges crossing the trigger level, irrespective of the rise/fall setting in the trigger menu.
- The “Counter” seems to use the same trigger level setting as the oscilloscope (Auto/Manual).
- The “Counter” increments in run mode and stops when the “Stop” button is pressed.
Whilst in stop mode, pressing the “Auto” button does not restart the “Counter”.
- To reset the count to “0”, reselect the “Counter” from the options menu.
- The “Counter” will not operate correctly if the oscilloscope voltage range is set to high.