The term hard key refers to all of the buttons on the instrument face except for the vertical row of 8 gray buttons adjacent to the right edge of the measurement display screen (the 8 submenu keys) and the horizontal row of 5 gray buttons below the measurement display screen (the 5 main menu keys).

The hard keys perform as follows:

Press this key to cancel any setting that is currently being made.

Press this key to finalize data input. Pressing the rotary knob performs this same function.

The four arrow keys (between the rotary knob and the Esc key) are used to scroll up, down, left, or right. The arrow keys can often be used (depending upon measurement selection) to change a value or to change a selection from a list. This function is similar to the function of the rotary knob. In some measurements, the Left/Right arrow keys change values by different increments than the Up/Down arrow keys or the rotary knob. The arrow keys are also used to move markers.

Press the Shift key and then press a number key to open the menu that is indicated in blue text above the number key. When the Shift key is active, its icon is displayed at the top‑right of the measurement display area between the battery charge indicator and the submenu label.

The Shift key is also used for UPPERCASE letters when entering text (refer to Text Entry.

Press this key to delete only one character, one number, or the range that is specified by the cursor.

Press this key to change the sign of numbers that are entered with the number keys.

Press these keys to directly input numbers. Number keys 1 through 9 are also used to open menus. Refer to the functions of the Shift Key.

Turn the rotary knob to change numerical values, to scroll through selectable items within a list, and to move markers. Values or items may be within a dialog box or an edit window.

Press the rotary knob to finalize the input function in the same manner as pressing the Enter key.

The 5 main menu keys are horizontally arranged adjacent to the measurement display screen and along its lower edge. These keys (buttons) have no printed labels. They are positioned to accompany virtual key labels that are displayed in the measurement display area. These main menu key labels change to match specific instrument Mode settings. Each Mode has a specific set of main menu keys. For details about the main menu keys, refer to the section Firmware Overview. For details about the Mode settings, refer to section Mode Selector Menu.

These 8 gray keys (buttons) have no printed labels. They are arranged adjacent to the measurement display screen along the right-hand edge. They are positioned to accompany virtual submenu key labels that are displayed to match instrument modes and measurement functions. The submenu label area is also called the Active Function Block (refer to Figure: Front Panel Overview). The virtual key labels change as instrument measurement settings change.