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FANUC Controller
Program/G-code · Basic · 5-15 minutes
Fanuc Alarm PS046 - Invalid Reference Return Command
PS046 alarm occurs when a G28 (or G30) reference return command is issued for an axis that either does not exist in the machine configuration, has not been properly homed, or violates reference return sequence requirements. This typically involves parameter mismatches between programmed axis names and machine axis configuration, or attempting reference return without meeting prerequisite conditions such as dog-type reference position setup or sequential axis homing requirements.
PS046
Fanuc Alarm PS046 - Invalid Reference Return Command
ILLEGAL REFERENCE RETURN COMMAND
Fanuc PS046: A reference return command (G28, G29, G30) was used in an illegal context or mode. The reference return command is not valid in the current machine state.
Root Cause Summary
PS046 alarm occurs when a G28 (or G30) reference return command is issued for an axis that either does not exist in the machine configuration, has not been properly homed, or violates reference return sequence requirements. This typically involves parameter mismatches between programmed axis names and machine axis configuration, or attempting reference return without meeting prerequisite conditions such as dog-type reference position setup or sequential axis homing requirements.
Safety
- Verify axis position
Causes and Fixes
- 1
Navigate to SYSTEM > PARAM and check parameters 1020 (1st axis name), 1021 (2nd axis), 1022 (3rd axis), 1023 (4th axis) to verify configured axis names (X=24, Y=25, Z=26, etc. in hexadecimal).
- 2
Review the program line causing PS046 and verify the axis address in the G28/G30 command matches one of the configured axis names from parameters 1020-1023.
- 3
Check parameter 1006 bit 0 (4th axis control) and parameter 1022 to confirm 4th axis is properly enabled if attempting reference return on A, B, or C axis.
- 4
Correct the program to use only valid configured axis names or add the required axis to machine parameters if physically present.
Parameter changes to axis configuration require POWER CYCLE and may need PMC ladder modifications for proper I/O assignment.
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