Quick Codes
These shortcuts work on most Fanuc controls (16i/18i/21i and compatibles). Try them in EDIT or MDI mode before calling anyone:
| Do this |
To do this |
P then RESET |
Clear error memory |
DELETE + RESET |
Clear system memory |
CAN + EOB |
Reset a edit error |
Any function key + CAN |
Turn the display off |
EOB + CAN |
Remove the overtravel inhibit |
Program switch must be ON for these next ones:
| Do this |
To do this |
RST + DEL + STR |
Clear all memory |
RESET (with param switch ON) |
Set parameters to initial values |
DEL + RST (with param switch ON) |
Clear all programs |
EDIT mode: O → -9999 → START |
Output all programs |
EDIT mode: O → program number → START |
Output a single program |
EDIT mode: O → -9999 → DELET |
Delete all programs |
EDIT mode: O → program number → DELET |
Delete a single program |
EDIT mode: O → -9999 → INPUT |
Input all programs |
EDIT mode: O → program number → INPUT |
Input a single program |
Fanuc Keypad — Full Function Reference
Everything below works on a standard Fanuc M/T series control. Keys are listed in the order they typically appear on the keypad.
Program Editing
| Key |
What it does |
| ALTER |
Replace the address or word at the cursor. Type the new value (e.g. X20.0) then press ALTER — the existing value is overwritten. |
| INSRT |
Insert what you've typed before the cursor position. Move cursor first, then type and press INSRT. |
| DELET |
Delete the address at the cursor. For a full block, enter the sequence number (e.g. N1) and press DELET. |
| EOB |
End of Block — inserts a ; to close a program line. Required at the end of every NC block. |
| CAN |
Cancel the current input before you've committed it. Works in EDIT and MDI mode. |
| INPUT |
Confirm input of an address or program block. Used when typing values or receiving from an external device. |
| OUTPUT / START |
Send a program or block out to an external device (tape, DNC, PC). |
Navigation
| Key |
What it does |
| CURSOR (↑↓) |
Move the cursor up and down through program blocks — same as arrow keys on a keyboard. |
| PAGE (↑↓) |
Scroll the screen when content exceeds one page. |
| O |
Address for program numbers. Programs run from O0001 to O9999. Note: O9000–O9999 are reserved for system macros and cannot be edited directly. |
| N |
Sequence numbers — optional block labels from N0001 to N9999. Use them to divide programs into sections (e.g. N1 roughing, N2 finishing). |
Word Addresses
| Key |
What it does |
| G |
Preparatory function — sets the machining mode (G00, G01, G02/03, G41/42, etc.) |
| X / Y / Z |
Axis movement commands |
| H |
Tool length compensation |
| D |
Tool radius compensation |
| R |
Arc radius (for G02/G03) |
| I / J / K |
Arc centre offsets from start point on X, Y, and Z respectively |
| F |
Feed rate. With G98 — feed per minute in mm/min. With G99 — feed per revolution in mm/rev. |
| S |
Spindle speed (RPM) |
| T |
Tool selection (typically two digits, e.g. T01) |
| M |
Miscellaneous / auxiliary function (M00, M01, M03, M08, etc.) |
| P |
Subroutine call parameter |
Display & Diagnostics
| Key |
What it does |
| PRGRM |
Show the current program content in the active mode (EDIT, MEM, or MDI). |
| POS |
Display axis positions. Toggle between absolute (machine coordinates) and relative (work offsets) with the soft keys. |
| OFFSET |
Tool length and radius compensation values — set and view your tool geometry offsets. |
| ALARM |
Show active alarms and error codes. Usually the fastest way to diagnose a fault. |
| DGNS PARAM |
Self-diagnosis screen and parameter editor (parameter switch may be required). |
| AUX GRAPH |
Display the tool path graphics — useful for verifying a program before running it. |
Mode Selection
| Key |
What it does |
| MEMORY (AUTO) |
Run the selected program automatically from memory |
| EDIT |
Create, modify, and delete programs |
| MDI |
Manual Data Input — type and execute a short sequence of blocks manually |
| HOME |
Return all axes to the machine reference (zero) position |
Program Execution Control
| Key |
What it does |
| RESET |
Return the program cursor to the start. Always press this after editing a block before restarting — otherwise the machine will alarm. |
| CYCLE START |
Begin or resume program execution |
| CYCLE STOP |
Pause program execution mid-cycle |
| PRG STOP |
Program stop — halts execution (shares function with M00) |
| SINGLE BLOCK |
Execute one block at a time — step through a program for testing |
BLOCK DELET (/ key) |
Skip blocks marked with / in the program — use this to bypass optional sections |
| OPT STOP |
Optional stop — pauses at M01 (shares function with the M01 code) |
| DRY RUN |
Run the program at mock feed rates — use to verify tool motion without cutting |
| PRG TEST |
Test run without executing M, S, or T codes — dry run for the full sequence |
Manual Operation
| Key |
What it does |
| JOG |
Manual continuous feed — hold to move an axis in a set direction |
| MPG |
Handwheel — rotate the portable handwheel to jog an axis in small increments |
| RAPID |
Override the feed rate to maximum rapid traverse speed for manual positioning |
| HOME / REF |
Return to machine reference point — establish the machine coordinate system |
| X+ / X- |
JOG the X axis positive or negative |
| Y+ / Y- |
JOG the Y axis positive or negative |
| Z+ / Z- |
JOG the Z axis positive or negative |
| 4+ / 4- |
JOG the 4th (rotary or index) axis |
| TRVRS |
Traverse — move all axes simultaneously per the current command |
| AXIS LOCK |
Lock all three axes — useful when checking the spindle and coolant without axis motion |
Spindle Controls
| Key |
What it does |
| SPDL CW |
Start spindle clockwise |
| SPDL CCW |
Start spindle counter-clockwise |
| SPDL STOP |
Stop the spindle |
| SPDL 100% |
Run spindle at the S value programmed in the current block |
| SPDL DEC / INC |
Decrease or increase spindle speed manually (override the programmed S value) |
Cutting Fluid
| Key |
What it does |
| CLNT ON |
Flood coolant on |
| CLNT OFF |
Flood coolant off |
| CLNT AUTO |
Coolant auto — follows the M08/M09 commands in the program |
Overrides & Safety
| Key |
What it does |
| OVERRIDE |
Feed rate override — adjust feed from 0% to 150% during a cycle (or per machine spec) |
| RAPID OVERRIDE |
Adjust the rapid traverse speed during manual positioning |
| EMERGENCY STOP |
Stop everything immediately — machine, spindle, coolant, all axes |
| THERMAL ALARM |
Spindle motor overload — let the machine cool and check the thermal relay |
| LUB ALARM |
Low lubricant — check the lubrication pump and oil levels |
| PROGRAM PROTECT |
Write-protect the program memory — prevents accidental deletion in EDIT mode |
| Z NEGLT |
Neglect Z axis commands — temporarily suppress Z moves (useful for air cutting tests) |
Useful Operating Modes
DNC Operation
Fanuc controls have limited program memory. When a program is too large to store internally, use DNC (Direct CNC) — the machine reads and executes the program directly from an external device (PC, tape, network) in real time, rather than loading it first. The program is not stored in memory.
Background Editing (BG-EDIT)
While the machine is running a program in AUTO/MEM mode, you can open a second program in the editor and make changes — without stopping production. Useful for pre-loading the next job's program while the current one is running.
Most of these keys and codes are standard across Fanuc 0i/16i/18i/21i series controls. Some functions — particularly parameter editing and memory clearing — require the relevant switch on the machine to be set before they work. When in doubt, check the machine's OEM manual.
