Using the knob allows positioning more discrete values on the same area as compared with the buttons and the set value is always shown in the same point (knob-center), i.e. it is not necessary to find what button is pressed, moreover, working knob looks more aesthetically than buttons.
These control knobs were specially designed to be used in USB oscilloscope, that's why there is a number of particularities to know when usefully operating these controls that can save your time and increase work comfort.
Methods to change the knob position:
1. Using the mouse - when left clicking on the knob (cursor takes a hand form) and moving the mouse but not exactly over the knob. When moving the mouse the knob cursor will be positioned along a line drawn from the center of the knob to the mouse cursor position, i.e. as effect of mechanical control knob. Upon clicking on the knob this element is within the input focus, i.e. can be key- or mouse wheel operated even if the mouse cursor is not on the knob. It is useful if you know that most of other usable elements are out of input focus, i.e. you can change the different triggering modes/levels and adjust the sampling period or peak-to-peak voltage by the mouse wheel.
2. Using the mouse wheel.
3. Using the keys Left, Right, Up, Down, Home, End, PageUp, and PageDown.
It is also necessary to note that when the mouse cursor is over the knob the prompt about the value to be set/set is shown on the status bar.