What causes FANUC alarm 152?

Too many tools have been assigned to a single tool group in the tool life management program, exceeding the system limit. A G10 data setting block in the part program is attempting to register more tools into a group than the control allows. The tool life management parameter for maximum tools per group is set too low for the number of tools being programmed. Copy-paste errors in the program caused duplicate or excess tool entries to be added to the same group. The CNC system has a fixed tool registration limit per group that varies by model and the program was written for a higher-capacity control.

How do I fix FANUC alarm 152?

1. Check the part program for G10 L3 or tool life management blocks and count how many tools are registered to the offending group. Compare this count against the maximum allowed by your specific Fanuc model. 2. Look up parameter No. 6813 or the relevant tool life management parameter on your control to find the maximum number of tools allowed per group. Adjust the program to stay within this limit. 3. Split the oversized tool group into two or more separate groups with fewer tools each, then update the program to call the correct group numbers. 4. If the machine application genuinely requires more tools per group, consult the Fanuc parameter manual to see if the maximum registration number can be increased via parameter change. Note this may require a system restart. 5. After making corrections, clear the tool life management data, re-register the tools within the new limits, and do a dry run to confirm the alarm is resolved.

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FANUC Controller

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

Alarm 152

Fanuc Alarm 152 - OVER MAXIMUM TOOL NUMBER

Fanuc Alarm 152 occurs when the number of tools registered in a single tool group exceeds the maximum allowable tool registration number defined by system parameters. This is typically caused by attempting to register too many tools in a magazine group, incorrect tool group parameter settings, or magazine configuration mismatches in the tool management system.

FANUCProgram/G-codeBasic15-30 minutes

152

Fanuc Alarm 152 - OVER MAXIMUM TOOL NUMBER

Illegal G Code

Root Cause Summary

Fanuc Alarm 152 occurs when the number of tools registered in a single tool group exceeds the maximum allowable tool registration number defined by system parameters. This is typically caused by attempting to register too many tools in a magazine group, incorrect tool group parameter settings, or magazine configuration mismatches in the tool management system.

Safety

Verify program functionality in single block mode after resolving alarm to prevent unexpected machine motion
Ensure proper workpiece setup before running modified or re-transferred programs
Be aware of potential rapid movements when testing programs. Keep hands and tools clear of the machine's moving parts.
Before modifying parameters, back up the current parameter settings to prevent data loss.
If the alarm persists after troubleshooting, consult a qualified CNC technician or Fanuc service representative.
Power down the machine before performing any hardware-related troubleshooting, such as checking connections or replacing components. Lockout/Tagout procedures should be followed.
Be cautious of electrical hazards when working inside the control cabinet. Ensure power is disconnected and properly grounded before touching any components.
Follow Lockout/Tagout procedures and power down machine before hardware troubleshooting
Back up parameter settings before modifications
Consult qualified CNC technician if alarm persists

Causes and Fixes

1
Navigate to SYSTEM > PARAM and check parameter 13220 (maximum tool registration number per group). Verify this value matches your magazine configuration and has not been inadvertently reduced.
2
Check parameters 13201-13204 (number of tools in magazine 1-4). Confirm the total tool count being registered does not exceed the capacity defined for the specific magazine group being used.
3
Access OFFSET SETTING > TOOL MANAGEMENT screen or MDI mode and review the current tool registration table. Count the number of tools assigned to the group triggering the alarm.
4
Delete unnecessary tool registrations from the group or redistribute tools across multiple groups if available. Alternatively, increase parameter 13220 if the physical magazine supports more tools and machine specifications allow.
Parameter 13220 must not exceed the physical magazine capacity or system maximum tool limit defined in parameter 13200.

DIY Feasiblehigh confidence

Call a technician if:

·Parameter modifications required
·Control software/option installation needed
·Persistent alarms after program corrections

Prevention

Use FANUC-certified CAM post processors
Regularly validate programs with program check function
Maintain updated G-code reference documentation for your specific control model
Implement program templates with verified G-code sequences

Common Mistakes

Mixing G-codes from different FANUC control generations
Assuming all G-codes work across all FANUC models
Not checking modal states before program execution
Copying programs between machines without verifying option compatibility

Related Alarms

010 011 020 021 151

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