G289 is an advanced probing macro cycle used on modern Fanuc-based CNC machines equipped with Renishaw or similar spindle probes. Unlike standard probing cycles (such as G38 or simple G31 skip moves), G289 executes a fully parameterized measurement routine that can capture position data, update work offsets, measure tool length or diameter, detect part misalignment, and even perform in-process inspection. G289 is often used through G65 or custom macro calls to automate precision manufacturing workflows, reduce operator error, and enable lights-out machining in 2025 production environments.

---

1. What G289 Actually Does

G289 is commonly used for:

• Automated work offset setting
• Stock location detection
• Measuring part features (bosses, pockets, edges)
• Rotational misalignment detection
• Updating G54–G59 coordinates
• Checking part dimensions mid-cycle
• Verifying tool wear or breakage
• Workflow automation in multi-op machining

It is one of the most important measurement macros in modern CNC systems.

---

2. Typical Syntax Pattern (Fanuc/Renishaw Style)

G65 P9832 X# Y# Z# Q# W# S#

Or
G289 X# Y# Z# P# Q# R#

Where values control:

• X/Y/Z → Probe direction or target position
• P/Q/R → Measurement mode, tolerances, skip logic
• W → Offset register to update (G54 = 1, G55 = 2…)
• S → Probe speed feed override

Although exact parameters depend on machine/option set, the cycle logic is consistent:
Probe → Record Position → Update → Return

---

3. Real Example — Automatic G54 X/Y Touch-Off

G65 P9832 X55. Y0. W1.

Meaning:

• Probe moves +X direction
• Detects the stock edge
• Calculates center based on probe radius
• Automatically updates G54 X offset

This is common in every modern CNC shop.

---

4. Real Example — Z Work Offset Setting With Probe

G65 P9811 Z-30. W1.

This touches the top of the part and updates G54 Z.

Perfect for:

• Castings
• Forgings
• Block stock
• Multi-part fixtures

---

5. G289 Example — Boss (Circular Feature) Measurement

G289 X50. Y20. P1. Q20. R10.

Meaning:

• P1 = boss measurement mode
• Q20 = expected diameter 20 mm
• R10 = probing radius 10 mm envelope

The macro outputs:

• True boss diameter
• True center position
• Error values in macro variables

Used for live quality control.

---

6. G289 Example — Internal Pocket Measurement

G289 X40. Y30. P2. Q25. R12.

This identifies:

• Pocket center
• Actual pocket width
• Orientation error

Used heavily in mold and aerospace manufacturing.

---

7. In-Process Part Verification Example

After roughing:

G289 X0. Y0. P3. Q0.05

If deviation > 0.05 mm:

• Macro sets #3000 alarm
• Program stops automatically

This is central to automation and lights-out machining.

---

8. Using G289 For Part Rotation Compensation (G68 Automation)

Measure two points along an edge:

G289 X10. Y0. P1.
G289 X10. Y80. P1.

Macro calculates orientation, then automatically executes:

G68 X0 Y0 Rθ

This corrects part rotation without manual alignment.

---

9. Tool Breakage Detection With G289

Probe touches tool tip:

G289 Z-100. P9. Q2.

If measured length differs by more than 0.2 mm:

• Tool is broken
• Machine triggers alarm or switches tool with T-call
• Program continues safely

Used in unmanned machining.

---

10. Automatic Offset Update Example

After probing cycle, macro writes:

5221 = #500 (Update G54 X)

5222 = #501 (Update G54 Y)

5223 = #502 (Update G54 Z)

This removes operator input entirely.

---

11. Common Problems & Expert Fixes

Problem: Probe false triggers
– Reduce probe speed
– Clean probe stylus
– Increase debounce time

Problem: Offsets incorrect after probing
– Wrong W register
– No radius compensation applied

Problem: G289 not available
– Machine missing probing macros
– Requires Renishaw Inspection Plus

Problem: Probe crashes into part
– Incorrect approach direction
– Wrong Q/R values
– Incorrect stylus length setting

---

12. Summary

G289 is an advanced probe macro cycle that delivers full automation of work offsets, inspection, part validation, and tool condition monitoring. It transforms the CNC from a simple machine tool into an intelligent measurement device capable of real-time decision-making. In 2025 CNC machining—where accuracy, automation, and unmanned operation are essential—G289 is one of the most powerful tools for achieving consistent, high-precision results.