G100+ G-Codes: OEM-Specific Functions and Advanced CNC Control

G100+ G-Codes: OEM-Specific Functions and Advanced CNC Control

Standard G-codes (G00–G99) cover basic CNC motions, drilling, tool changes, and feedrate modes. But many CNC controllers also support G100+ series codes — these are custom or extended G-codes, often OEM-specific or reserved for internal functions.

Understanding these advanced codes helps unlock the full potential of your CNC machine.

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🧠 What Are G100+ G-Codes?

• Typically non-standard, OEM-assigned, or hidden functions
• Used for automation, probes, safety routines, macros, or advanced motion
• Not documented in public ISO G-code standards — check your machine manual or controller documentation

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📋 Common Examples

G-Code	Controller	Function Description
G100	Fanuc (varies)	Custom macro call / interpolation
G101	Haas	“C-axis” motion in live tool lathes
G103	Haas	Block buffering limit
G112	Haas	Cartesian-to-polar interpolation for milling
G120	Siemens	Synchronous spindle control
G140+	Okuma / Mazak	Adaptive high-speed motion commands

⚠️ These codes behave differently depending on the machine brand and model!

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🔧 Fanuc G100 Example (Macro Link)

Some Fanuc machines use:

G100 P1

To call a custom macro (like O9010) with arguments.

Or:

G100 X... Y... Z...

For custom interpolation routines tied to internal PMC logic or user macros.

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🧪 Haas G112 Example (Polar Milling)

G112      ; Enable polar interpolation mode
G01 X25.0 C180.0 F300
G113      ; Cancel polar interpolation

Used for engraving or wrapping geometry around cylindrical parts with live tooling.

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🛠️ G103 (Haas): Block Buffering Control

G103 P1 ; Allow 1 block of lookahead

Useful for:

• Pausing long curves
• Forcing real-time operator sync
• Diagnostic routines

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⚠️ Safety & Compatibility Notes

• NEVER use G100+ codes from another controller brand on your machine
• Always consult:
• Machine builder manual
• Control-specific G-code reference
• OEM documentation
• Unrecognized G100+ codes may result in alarm, skip, or unpredictable behavior

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🧩 Custom Implementation in PLC-Driven Machines

Some builders (especially with Fanuc, Siemens, Mitsubishi) assign G100–G199 to ladder-linked functions such as:

• Pallet change
• Vacuum chucking
• Safety interlock routines
• Custom axis movement logic

These are handled outside the G-code interpreter.

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✅ Best Practices

• Log and document all custom G-code behavior in your company’s setup sheets
• Lock G100–G199 behind admin-level MDI access if needed
• Use only when you fully understand the logic
• Back up macro programs (O9000 series) before editing G100-related routines

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🧠 Summary

Range	Standard?	Risk Level	Notes
G0–G99	Yes	Low	ISO standard, universal across CNCs
G100–G199	No	Medium–High	OEM/controller-specific, varies greatly

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🧪 Pro Tip for Integrators

If you’re building automation systems, consider using G100–G199 space to link:

• Probing macros
• Pallet changers
• Conveyor start/stop routines
• Safety zones and part presence logic

Use G65, M98, or G100 to trigger them cleanly and keep programs modular.

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▶️ Coming Up: M198 – Remote Subprogram Calls from External Storage (DNC)