RIGOL DS6000 Series - Manual (Page 144)

RIGOL 6 To Make Measurements
DS6000 User’s Guide 6-20
Frequency Counter Measurement
The hardware frequency counter supplied with this oscilloscope can make more
precise measurement of the signal frequency.
Press MEAS  Counter to select anyone of CH1-CH4 as the source. The
measurement result is displayed at the upper right corner of the screen and you can
identify the current measurement source according to the color of the icon. The
following figure is the result of the frequency measurement of the signal from CH1.
If “OFF” is selected, the frequency counter measurement function is turned off.