What the Keys on the CNC Milling Control Panel Mean

In this article, part of our machine training lecture notes section, we’re covering the CNC milling control panel and what its keys mean. Here we’ll go over the screen menus of Fanuc CNC vertical machining centers and what the keys on those menus do.

CNC Milling Control Panel

The part of a CNC machine tool that lets you enter data and programs into the machine, shows the user the machine’s status and motion via its screen, and lets you monitor the program simulation, is called the control panel.

POSITION (POS) key: Lets us see the cutter’s position on the X, Y, Z axes on screen.

PROGRAM key: Used to enter a program or bring a running program up on screen

OFFSET SETTING key: Brings up the menu needed to define the cutting tool’s reference point

cnc milling keys POS, PROG, OFFSET SETTING, SHIFT, CAN, INPUT, SYSTEM, MESSAGE

SHIFT key: Used to type the secondary character printed on some numeric and alphabetic keys

SYSTEM key: Brings up the menus related to the CNC machine’s system settings

ALERT key: Used to delete the last character typed.

PAGE UP/DOWN keys: Used to move to the page above or below within menus

CAN key: Used to delete the last character while writing a program.

MESSAGE key: Used to view the alarm message

INSERT key: Used to type a character into a line while writing a program, or to enter alphabetic or numeric values while in the menus

HELP: Used to enter the CNC screen’s help menu

INPUT key: Lets you enter data or any value related to the machine

CUSTOM GRAPH key: Used to bring up a graphical display of the running program.

DELETE key: Used to delete a typed character or delete any numeric value entered within the menus.

cnc milling keys CUSTOM GRAPH, ALERT, INSERT, DELETE, ALTER

ALTER key: Used to carry out certain secondary functions.

EOB key: Used to place the (;) mark at the end of a line while writing a CNC program (End Of Block)

ARROW KEYS: Used to move the cursor on screen and switch between menus.

RESET key: Used to stop the running program.

Fanuc Screen Standard

On Fanuc control panels, the screen is typically 8.4-10.4 inches in size, and there are both touchscreen and keypad versions.

Emergency Stop Button

The red mushroom-head emergency stop button sits in the most visible spot on the panel and, when pressed, instantly stops all axis motion.

Mode Selector Switch

The mode selector switch on the panel is used to switch the machine between MDI, Automatic, Manual, and Edit modes.

Meaning and Function of the CNC Operation Control Keys

cnc control panel operation control keys

On CNC milling machines, there are numerous switches and keypads that handle functions such as controlling slide motion, manually adjusting parameters like spindle speed and feed rate, and moving cutters in the tool magazine. A general overview is shown in the figure

EMERGENCY STOP: This button terminates all functions of the CNC machine. It’s a safety button. It should be used when there’s a hazard. Using it routinely is not correct practice.

Feedrate override: This dial is used to increase or decrease the feed rate values in a CNC program loaded on the machine, as a percentage. 100% represents the feed rate value in the program, values below 100% are lower than the program’s feed rate values, and values above 100% are higher than the program’s feed rate values

Spindle override: This dial is used to decrease or increase the spindle speed set on the machine or entered in the program loaded into the CNC machine. 100% is the current spindle speed, and 50% sets the speed to half of the given speed.