What causes FANUC alarm 046?

Incorrect G-code command for returning to a reference position. Syntax error in the P address command specifying the reference position. Attempting to return to a reference position that has not been properly set.

How do I fix FANUC alarm 046?

1. Check your G-code program and look for any commands related to returning to a second, third, or fourth reference position. Ensure the syntax is correct, especially the P address command. 2. Verify that the reference positions have been properly set earlier in the program using G28, G30, or other reference position commands. 3. If the reference positions have been set, try removing the return command and see if the program runs without the alarm. 4. Consult your Fanuc control documentation or programming manual to ensure you are using the correct G-code commands and syntax for returning to reference positions.

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FANUC Controller

Program/G-code · Intermediate · 15-30 minutes

Alarm 046

Fanuc Alarm 046 - ILLEGAL REFERENCE RETURN COMMAND

Alarm 046 occurs when the CNC detects an improper reference return command (G28, G30, G30.1, etc.) attempting to return to the 2nd, 3rd, or 4th reference position with an incorrect or missing P address specification. The system expects a valid P code (P2, P3, or P4) to designate which reference position is targeted, and the alarm triggers when this specification is illegal, missing, or conflicts with parameter settings that haven't enabled multiple reference positions.

FANUCProgram/G-codeIntermediate15-30 minutes

046

Fanuc Alarm 046 - ILLEGAL REFERENCE RETURN COMMAND

FANUC ALARM 46

Root Cause Summary

Alarm 046 occurs when the CNC detects an improper reference return command (G28, G30, G30.1, etc.) attempting to return to the 2nd, 3rd, or 4th reference position with an incorrect or missing P address specification. The system expects a valid P code (P2, P3, or P4) to designate which reference position is targeted, and the alarm triggers when this specification is illegal, missing, or conflicts with parameter settings that haven't enabled multiple reference positions.

Causes and Fixes

1
Review the NC program line that triggered the alarm. Verify G30 commands include a valid P address: G30 P2 (2nd reference), G30 P3 (3rd reference), or G30 P4 (4th reference). Note that G28 returns to 1st reference and does not use P address.
2
Check program syntax for correct format: G30 P_ X_ Y_ Z_ (intermediate point) or G30.1 P_ (direct return). Ensure no spaces or incorrect characters between G30 and P address.
3
Correct the program by specifying valid P code. Example: Change 'G30 X0 Y0 Z0' to 'G30 P2 X0 Y0 Z0' for 2nd reference position return.
4
Re-run the program after editing. If alarm persists, verify the P value is within the range 2-4 and matches an enabled reference position in parameters.

DIY Feasiblehigh confidence

Call a technician if:

·Parameter backup/restore needed
·Machine coordinate system corruption suspected
·Multiple reference position alarms persist

Prevention

Always verify reference position parameters before programming G28/G30 with P addresses
Use consistent P address values across programs
Document configured reference positions for operators

Common Mistakes

Using P1 or P0 in reference return commands
Forgetting to configure parameter 1241-1252 values
Not enabling reference positions in parameter 1240

Related Alarms

010 011 090 091

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