What causes FANUC alarm 311?

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 311?

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 311 specific remedy. 5. Contact Fanuc service if the alarm persists after basic troubleshooting.

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FANUC Controller

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

Alarm 311

Fanuc Alarm 311 - CALLED BY FILE NAME FORMAT ERROR

Alarm 311 occurs when the CNC detects an incorrectly formatted file name in a subprogram call (G65 Pxxxxxx, M98 Pxxxxxx) or macro call statement. This typically happens when file name calling is enabled (Parameter 3107#0=1) but the called program name does not conform to Fanuc's required O-number or file name format specifications, or when illegal characters or invalid syntax are used in the call command.

FANUCProgram/G-codeBasic15-30 minutes

311

Fanuc Alarm 311 - CALLED BY FILE NAME FORMAT ERROR

SYSTEM ALARM 311

Root Cause Summary

Alarm 311 occurs when the CNC detects an incorrectly formatted file name in a subprogram call (G65 Pxxxxxx, M98 Pxxxxxx) or macro call statement. This typically happens when file name calling is enabled (Parameter 3107#0=1) but the called program name does not conform to Fanuc's required O-number or file name format specifications, or when illegal characters or invalid syntax are used in the call command.

Causes and Fixes

1
Navigate to SYSTEM > PARAM and verify Parameter 3107#0 (file name call enable). If set to 1, file name calling is active and strict format rules apply.
2
Review the calling program line that triggered the alarm. Check for invalid characters in the file name (only alphanumeric and underscore typically allowed), spaces, incorrect bracket usage, or names exceeding 32 characters.
3
Correct the format to valid syntax: M98 P<filename> or G65 P<filename> where filename matches the actual stored program name exactly, including case sensitivity if Parameter 3107#1=1.
4
Verify the called program exists in memory by checking PROG > DIR listing and ensure the name exactly matches the call statement including any extension requirements set by Parameter 3107 settings.

DIY Feasiblehigh confidence

Call a technician if:

·File system corruption detected
·Parameter changes required beyond operator level
·Memory card hardware failure

Prevention

Use standardized naming conventions for all programs
Regularly backup programs to prevent file corruption
Document all subprogram dependencies
Test program calls after any file system changes

Common Mistakes

Using spaces in file names
Mixing O-number and file name calling methods
Not verifying file existence before calling
Incorrect quote usage in file name calls

Related Alarms

078 310 312 313

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