What causes FANUC alarm 5306?

Machine system or function indicated by the alarm name has detected a fault. Control parameter or configuration error related to the alarm condition. Hardware component fault on the CNC or machine. Part program error or illegal operation for the indicated function. Machine interlock or safety condition not satisfied.

How do I fix FANUC alarm 5306?

1. Note the alarm number and check the Fanuc alarm screen for any sub-code or additional details. 2. Identify the specific machine system or function from the alarm name. 3. Power cycle the machine to clear transient faults. 4. Consult the Fanuc parameter or operator manual for alarm 5306 specific remedy. 5. Contact Fanuc service if the alarm persists after basic troubleshooting.

axismd.ai

FANUC Controller

System · Intermediate · 30-60 minutes

Alarm 5306

Fanuc Alarm 5306 - MODE CHANGE ERROR

Fanuc alarm 5306 MODE CHANGE ERROR occurs when the CNC system detects an invalid or prohibited mode transition attempt, typically during system startup, parameter loading, or when switching between operating modes (MEM, MDI, EDIT, etc.). This alarm indicates that the CNC detected a mode change request that conflicts with current system state, I/O conditions, or parameter settings that restrict mode transitions.

FANUCSystemIntermediate30-60 minutes

5306

Fanuc Alarm 5306 - MODE CHANGE ERROR

SYSTEM ALARM 5306

Root Cause Summary

Fanuc alarm 5306 MODE CHANGE ERROR occurs when the CNC system detects an invalid or prohibited mode transition attempt, typically during system startup, parameter loading, or when switching between operating modes (MEM, MDI, EDIT, etc.). This alarm indicates that the CNC detected a mode change request that conflicts with current system state, I/O conditions, or parameter settings that restrict mode transitions.

Causes and Fixes

1
Navigate to SYSTEM > PARAM and check parameter 3107 (Mode Group Selection) and 3108 (Mode Selection Method). Note current settings and verify they match machine specifications.
2
Check parameter 3201 bits 0-3 which enable PMC mode change control. If bit 0=1, external mode change signals are enabled. Verify PMC ladder logic controlling G54-G57 (mode selection) addresses.
3
Review parameter 3202 (Mode Change Disable) to check if specific modes are prohibited. Set to 0 to allow all modes or adjust bits to enable required operating modes.
Changing mode restriction parameters may affect machine safety interlocks. Consult machine builder documentation before modification.
4
After parameter changes, perform a full power cycle (not just RESET). Verify mode changes function correctly through all required modes: MDI, MEM, EDIT, JOG, HANDLE.

DIY Feasiblehigh confidence

Call a technician if:

·Mode switch replacement required
·PMC ladder program corruption
·Multiple simultaneous system failures

Prevention

Regular PMC program backups
Periodic mode switch cleaning
Parameter backup maintenance
Proper shutdown procedures

Common Mistakes

Forcing stuck mode switch
Changing parameters without backup
Ignoring safety interlock requirements
Not checking for active processes before mode change

Related Alarms

5307 5308 5309 2010 2011

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.