Comprehensive Parameter Guide for FANUC CNC Controls

FANUC controllers are the heart of CNC machines, and correct parameter settings are what let them reach maximum performance. In this guide we cover the most critical parameters, functions, and setup procedures across different FANUC control series in detail.

📌 REFERENCE POINT (HOME) SETTINGS

1815 – APC and APZ (Reference Point Establishment)

Applies to: All CNC lathes and machining centers

This parameter is used to establish the reference point (home position) on machines equipped with an absolute encoder (Absolute Pulse Coder).

How to do it:

1. Power off the machine

2. Using the handwheel, move the X and Z axes to the reference point

3. In parameter 1815, set the APC and APZ bits (bits 4 and 5) to “1”

4. Power the machine off and back on

⚠️ Warning: After a battery replacement the APC and APZ bits can reset. If the reference point is lost, this procedure must be repeated.

1850 – Grid Shift

Applies to: All FANUC controls

Used to fine-tune the reference point. It adds an extra shift to the reference point equal to the value entered. For Grid Shift to be active, parameter 1002#2 must be “1”.

🎯 DECIMAL POINT SETTINGS

3401#0 (DPI) – Decimal Point Suppression

Applies to: 0i-MB controls

Removes the requirement to use a decimal point (.) in FANUC programming.

• DPI = 1: Values entered without a decimal point are read as mm/1000 (microns)
• DPI = 0: The standard decimal-point requirement remains in effect

P.15#7 – Cancel Decimal Point in Program

Used to cancel decimal points written during the program.

🔄 4TH AXIS (ROTARY AXIS) SETTINGS

4th Axis Addition Parameters

Applies to: 0i-MB / 0i-MC controls

Note: The correct Motor ID (2020) must be entered and the machine must be restarted.

4th Axis Cancellation

Applies to: 0i-MC control

• Bit 7 of 1005 and 1012 = “1” → 4th axis disabled
• Bit 7 of 1005 and 1012 = “0” → 4th axis enabled

4th Axis 360° Rollover

1006#0 = 1 → After a 360° revolution the 4th axis resets the machine position value.

18i-MB 4th Axis Commissioning

Bits #0 and #3 of 3115 must be “0” (3115=00000000).

🏗️ HIGH-SPEED MACHINING (AICC)

G5.1 Q1 / G5.1 Q0

Applies to: 0i-MC control

A high-precision machining mode that automatically reduces feedrate at corners.

M03 S... (after the spindle reaches speed)
G5.1 Q1  (high-speed mode active)
... machining code ...
G5.1 Q0  (mode off - before M30)

🎛️ SPINDLE SETTINGS

M19 Spindle Orientation Setting

M19 setting parameters across different control series:

When adjusting with 4077: it works over 4096 pulses. For a 90° change, add or subtract 1024 from the current value.

4030 – Spindle Soft Start/Stop

Applies to: Twinhorn machines

If the spindle knocks during start-up or stopping, set 4030 = 12000.

3735 – Spindle Minimum Speed Setting

Applies to: 0i-MD Twinhorn VP 1500

Minimum clamping speed of the spindle motor.

• Usually takes a value between 0 and 5
• Example: 20 is entered and checked as a percentage

🛠️ TOOL CHANGE SETTINGS

Tool Numbering (0-MD Control)

Turret Reference Establishment (Lathe)

• PMM parameter 11#0 = 1 → Establishes the turret reference (first set to “0” and rotate the turret, then set to “1”)

D 401#0 – Turret Position Loss (Goodway TB 150)

This bit becomes “1” when the turret loses position. Setting it to “0” allows the turret to rotate again.

🖥️ DISPLAY AND LANGUAGE SETTINGS

Changing the Language

Turning the Graphic Screen On/Off

3112#0 (SGD)

• = 0: The graphic screen is shown
• = 1: The Servo Waveform Diagnosis screen is shown instead (the graphic screen does not appear)

3123 – Screen Saver

Parameter 3123 sets the screen-saver timeout in minutes.

8940 – Custom Name on the Startup Screen

To change the name shown on startup, enter a 10-character text string in parameter 8940.

🔧 BALLSCREW BACKLASH SETTINGS

535 – X-Axis Ballscrew Backlash

536 – Z-Axis Ballscrew Backlash

Applies to: 0-T control

Enter the value in microns (µm). It compensates for the play that occurs when the axis reverses direction.

🔌 DATA SERVER CONNECTION SETTINGS

Accuway Data Server (M198 Command)

Twinhorn 0i-MB Data Server

⚙️ OTHER IMPORTANT PARAMETERS

5015 – Inner Diameter Adjustment Parameter (0i-TB Lathe)

• Subtracted if smaller, added if larger

5016 – Outer Diameter Adjustment Parameter (0i-TB Lathe)

• Subtracted if smaller, added if larger

1466 – Remove Pass Dwell (0i-TC Lathe)

Setting 1466 = 0 removes the dwell while taking a pass.

2496 – Chuck Open/Close Time (0i-TB Lathe)

Changing the timer value shortens the chuck open/close time. Example: 2496 = 496

6710 – Part Counting with M90 (0i-TC Lathe)

Set 6710 = 90. Writing the M90 command above the M99 line enables part counting on Focus machines.

3402#7 – Automatic Mode After M30 (0i-TC Lathe)

When = 1, seeing M30 or pressing Reset makes the machine automatically accept the G96 and G00 codes.

1401#6 – Dry Run Rapid Speed (0i-MC)

When set to = 1, the rapid speed can be controlled in Dry Run mode.

6200#7 – Dry Run

Settings related to the Dry Run function.

518 and 519 – Idle (Rapid) Axis Speeds

Define the rapid axis movement speeds.

60#5 – Motor Load Page

When set to = 1, the motor load page opens.

907#3 – Enable 3rd Axis (Machining Centers)

= 1 enables the 3rd axis.

22#0 and 22#1 – Absolute Encoder References (TA 32)

After the references are set:

• 22#0 = 1 → X axis accepts the reference
• 22#1 = 1 → Z axis accepts the reference.

569#0 – System Reset to Start

On vertical machines, if the movement is interrupted mid-way at the tool-change position, set = 1 to return the system to the start.

2113 – Axis Motor Setting

Used for axis motor settings.

5231, 5232, 5233 – Rigid Tapping (M29) Parameters

Gear-ratio settings for rigid tapping:

• 5231: Position coder tooth count (1st gear)
• 5232: Position coder tooth count (2nd gear)

5114 and 5115 – G73 / G83 Peck Return Value and Clearance

5114 sets the return (retract) amount after each peck in the high-speed peck drilling cycle (G73 on milling controls). 5115 sets the clearance in the peck drilling cycle (G83 on milling controls): after retracting to the R point, the tool rapids back down and switches to cutting feed this distance above the bottom of the previous peck. Both values are in mm (or inch) according to the input unit. Neither parameter has anything to do with the G84 tapping cycle. On lathes (T series), bit 2 (RTR) of parameter 5101 selects which of the two G83 uses.

Shop note (0i-MD, Twinhorn VP 1500): on this machine 5115 is set to a maximum of 2.00 mm. This is a workshop practice, not a manufacturer limit. The descriptions follow the FANUC 0i-F Parameter Manual (B-64610EN) and are identical in the 0i-D User’s Manual (B-64304EN-2).

3104#6 – Tool Length Display (18i-MB)

= 1 → Subtracts the tool length and shows the remaining distance.

3706#6 – Tool Length Display (0i-MC)

Shows the tool length without adding it.

K1.2 – Disable Way Lubrication Pressure Switch (Twinhorn)

= 1 → Disables the way lubrication unit’s pressure switch.

🏭 RIFA MACHINE-SPECIFIC SETTINGS

Dual Pallet Position Settings

Pallet position setting (in programs O9001 and O9002):

Tool Change Position:

M19 Position Setting (inside the macro):

• #1132 = 1430 (changed inside O9001)

Sensor Checks:

• X4.4 = 1 (the window switch separating the two pallets)
• X5.2 = 0 (sensor indicating the pallet is not clamped)
• K10.4 = 1 (pallet down)
• K10.2 = 0 (pallet clamped)

Rifa Horizontal Machining Center

3104#6 and #7 = 1 → The program’s “Z” axis values become the same as the absolute values.

Rifa Tool Change Z-Axis Value (O9001)

• 6930 = 30100 + 0.1
• 6950 = 29900 – 0.1

💾 PROGRAM COPYING AND TRANSFER

903#7 – Program Copying (0-MD Control)

Enables the copy function.

0i-MD Running and Transferring from a Card

TAPE → PROGRAM → Right arrow → DIR → OPRT → Right arrow → REFRESH

The card’s contents are displayed.

PLC Loading for Accuway Program Restart

SYSTEM + PMC + I/O + MCARD + READ + EXEC + YES + COMPLETE + ←
22108758 → DISPLAY
G22108758 → EDIT
MCARD + FREAD + EXEC + COMPLETE + RUN + YES

9930#0 = 1 – Program Restart

Enables the program restart function.

📊 FOCUS AND SERVO MOTOR PARAMETERS

Focus Motor Adaptation Parameters

Focus Servo Turret Reset

1. Power off the machine

2. When powering the machine back on, the turret must be in the reference position at tool 1

3. Hold one hand on the hydraulics and one hand on the turret rotation control

4. The counter must read 0

Focus FCL-140

K1#0 = 1 → The part counter stops the machine once the target count is reached.

Which parameters and behaviours changed from 0i-C to 0i-D? (machining center)

FANUC collected the points that trip up anyone moving programs or parameter lists from a 0i-C to a 0i-D machine in the appendix “Differences from Series 0i-C” of the 0i-D machining center user’s manual (B-64304EN-2). The table below summarises the ten items from that appendix that affect operators and programmers directly. The source is the milling (M series) manual; items on G43/G44, drilling cycles and G60 are milling-specific, the rest belong to the control core and apply to lathes as well. Parameter numbers and bits are given exactly as printed; compare them with your machine builder’s parameter list and take a backup before changing anything.

The appendix also lists smaller differences: the G31 skip bits (6200#4 HSS instead of 6200#5 SLS; PS0035 on torque-limit skip), P in an M198 external call always being a program number and MDI use via 11630#1 (MDE), parts-count and run-hour ranges growing to 9 digits (No. 6710–6713, 6750–6758), the handwheel multiplier range widening to 1–2000 with No. 7110 removed, and a negative value in the ,C/,R chamfer and corner-R command giving PS0006. The 5114/5115 peck-drilling parameters on this page have the same meaning in both series.

Frequently asked questions: how do I change a parameter on a FANUC?

What are the exact steps to change a parameter on a FANUC 0i?

1. Put the machine in MDI mode (or press emergency stop).
2. Press OFFSET/SETTING and select the [SETTING] soft key.
3. Move the cursor to PARAMETER WRITE, type 1 and press INPUT (on some series [(OPRT)] → [1: ON]). Alarm 100 appears; that is normal.
4. Press SYSTEM and select the [PARAM] soft key.
5. Type the parameter number and press [NO.SRH] to jump to it.
6. Type the new value and press [INPUT]. For bit-type parameters, enter all eight digits from bit 7 to bit 0 together (for example 00000001).
7. Return to the SETTING screen and set PARAMETER WRITE back to 0.
8. Press RESET to clear alarm 100.

Back up the parameters before the change and consult the builder’s parameter list; a wrong axis, servo or stroke-limit parameter can crash the machine.

Why does alarm 100 (PARAMETER WRITE ENABLE) appear?

Because parameter write permission has been left on. It is not a fault: set PARAMETER WRITE to 0 and press RESET. Do not make a habit of running the machine with write enabled; the next operator can change a parameter by mistake.

What does alarm 000 (PLEASE TURN OFF POWER) mean?

The parameter you changed only takes effect after the power is switched off and on (axis, servo and system configuration parameters, for example). The alarm cannot be cleared with RESET; power the machine off and on. The parameter manual marks these parameters with a “power must be turned off” note.

How do I find the parameter number I am looking for?

On the SYSTEM → [PARAM] screen, type the number and press the [NO.SRH] soft key; there is no need to page through. Axis-type parameters (such as 1320 stroke limit) show one line per axis.

How do I back up before changing a parameter?

The safest way is to enter the BOOT screen at power-on and take an SRAM backup to a memory card; it contains parameters, offsets and programs together. For a parameter-only backup, SYSTEM → [PARAM] → [(OPRT)] → [PUNCH] writes the parameters to a memory card or to a PC over RS-232. The method is described in our FANUC SRAM backup guide.

I entered a wrong parameter and the machine behaves strangely. What now?

Restore that parameter to its old value immediately; the old value is in your backup list or in the builder’s parameter list. If it affects axis motion, power the machine off and on and make the first move by hand at low override. If you do not know which parameter you changed, restoring the SRAM backup is the quickest way, which is why the backup must be taken before the change.

Why does my 0i-C program raise alarms on a 0i-D?

The three most common reasons: lines that write parameters from the program need G10 L52 on a 0i-D instead of G10 L50; a macro call (G65 or a macro-calling M code) that is not at the start of its block gives PS0127; “GOTO 0” and sequence numbers that are not at the start of a block give PS1128/PS0128. In drilling cycles a missing Q value always gives PS0045 on a 0i-D. Look the alarm number up in the table above.

Can I copy a 0i-C parameter list to a 0i-D machine as it is?

No. Many bits were removed and many parameters moved to new per-axis numbers (for example 1660 instead of 1770/1771, 1735 instead of 1730/1731, 5105#3 instead of 5101#6). Load only the parameter list the machine builder supplies for the 0i-D; enter the individual values you want to carry over from the 0i-C (backlash, pitch error, spindle settings) by hand after checking their new numbers, and take an SRAM backup first.

⚠️ DISCLAIMER

⚠️ MENTOR CNC DISCLAIMER
All technical information, parameter numbers, and procedural steps in this blog post were obtained from machine manuals and technical documentation. However, these details may vary depending on your machine’s brand, model, manufacturer configuration, PLC software, and parameter structure.
For this reason, always record the original values of any parameter before changing it during testing. This lets you revert the change if something goes wrong.
If you have not previously made a Leader PLC, software, or parameter change, be sure to get help from an authorized service provider. Full responsibility for any actions taken rests with the user. Mentor CNC and its content authors cannot be held liable for any malfunction, data loss, or damage that may result.

This guide was prepared for CNC operators and technicians working with FANUC controllers. Always remember to reference your machine’s original documentation as well.

Related Pages

The notes on this page include field observations specific to different FANUC series and certain machine manufacturers. For a more comprehensive, general reference based on your control unit, see:

• FANUC 0-MC Vertical Machining Center Parameters, G-Codes, and Alarm Solutions
• FANUC Series 0 / 00 / 0-Mate Machining Center Complete Parameter Reference
• Mitsubishi M70/M700 Program and Machining Parameter Settings
• Mentor CNC Homepage