What causes FANUC alarm 359?

The G28 command was used to return to a reference position, but the reference position has not been set for one of the axes in the composite axis group. The program is attempting to use G28 to return to a reference position on a composite axis, but the reference position has not been properly established. A reference position has not been properly set for one of the axes that is part of the composite axis group, preventing the G28 command from functioning correctly.

How do I fix FANUC alarm 359?

1. Check the program to ensure that a valid reference position has been set for all axes in the composite axis group prior to using the G28 command. 2. Review the axis configuration to confirm that all axes in the composite group have been properly homed and their reference positions established. 3. Verify that the composite axis group has been defined correctly in the machine parameters and that all axes are properly associated. 4. Consider using individual axis commands (G28 X0 Y0 Z0) instead of the composite G28 command until the reference position issue is resolved. 5. If the problem persists, consult the machine documentation or contact the Fanuc technical support team for further assistance.

axismd.ai

FANUC Controller

Servo/Axis · Intermediate · 30-60 minutes

Alarm 359

Fanuc Alarm 359 - G28 IN COMP MODE WITH REF POS NOT FIXED

Fanuc Alarm 359 occurs when a G28 (automatic return to reference point) command is issued to a composite axis during composite control mode, but the other axis component of the composite pair has not completed reference position return. The composite axis cannot execute G28 safely because the reference position of the paired axis is not established, preventing proper coordinate system calculation.

FANUCServo/AxisIntermediate30-60 minutes

359

Fanuc Alarm 359 - G28 IN COMP MODE WITH REF POS NOT FIXED

FANUC ALARM 359

Root Cause Summary

Fanuc Alarm 359 occurs when a G28 (automatic return to reference point) command is issued to a composite axis during composite control mode, but the other axis component of the composite pair has not completed reference position return. The composite axis cannot execute G28 safely because the reference position of the paired axis is not established, preventing proper coordinate system calculation.

Causes and Fixes

1
Check DIAGNOSIS screen > CURRENT POSITION display. Navigate to SYSTEM > DIAGNOSIS > #0300 (Reference Position Return Status). Verify bit status for all axes involved in composite control - bit should be '1' when reference position is established.
2
Perform manual reference position return (G28 or REF button on MDI panel) for all physical axes that comprise the composite axis. Ensure all axes individually complete reference return before attempting composite G28.
3
Verify composite axis parameter settings. Check SYSTEM > PARAM > #1023 (Composite Axis Control Base Axis) and #1024 (Composite Axis Control Additional Axis) to confirm correct axis pairing configuration.
4
Review parameter #1815.0 (Reference Position Return Required) - if set to '1', all axes must complete reference return before composite motion. Confirm this matches machine requirements and execute reference return sequence accordingly.

DIY Feasiblehigh confidence

Call a technician if:

·Encoder hardware failure detected
·Parameter corruption persists after restoration
·Composite axis mechanical binding during reference return

Prevention

Always perform individual axis reference return before enabling composite control after power-up
Regularly backup reference position parameters
Monitor encoder feedback quality during composite operations
Implement proper power-down procedures to preserve reference positions

Common Mistakes

Attempting G28 immediately after power-up without individual axis reference return
Enabling composite control before both axes have established reference positions
Ignoring encoder alarm history when troubleshooting reference position issues
Modifying composite parameters without understanding axis interdependencies

Related Alarms

401 414 435 360 361

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.