What causes FANUC alarm 1101?

Custom macro interrupt (M96/M97) triggered during a canned cycle execution where move commands are not permitted. Macro interrupt with motion commands fired while the machine was in a tool length measurement or probing state. Interrupt routine containing axis movement called during a state where the CNC cannot process motion, such as during a G31 skip function. Macro interrupt triggered while in a single block stop or feed hold condition that blocks motion execution. Incorrect macro interrupt program structure where a move instruction exists but the interrupt was called from a non-motion-capable modal state.

How do I fix FANUC alarm 1101?

1. Review the custom macro interrupt program (typically called by M96) and identify any axis move commands (G00, G01, etc.) inside the interrupt routine that may be executing at an invalid time. 2. Check the main program at the line where the interrupt was triggered and confirm whether the active G-code modal state (such as a canned cycle G80-G89 or G31) prohibits motion commands from an interrupt. 3. Temporarily disable the macro interrupt by removing or commenting out the M96 command and run the program to isolate which block triggers the conflict. 4. If the interrupt must contain motion, restructure the main program so the interrupt is only active during modal states that allow axis movement, using M97 to cancel the interrupt during restricted sections. 5. Check parameter 6003 bit settings which control macro interrupt behavior and confirm they match the intended interrupt type for your application. 6. Consult the macro program logic to ensure the interrupt flag or signal triggering the interrupt is not firing prematurely during a restricted G-code block.

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FANUC Controller

Program/G-code · Advanced · 45-90 minutes

Alarm 1101

Fanuc Alarm 1101 - ILLEGAL CNC STATEMENT IRT

Alarm 1101 occurs when a custom macro interrupt (M96/M98 or G10 L1) containing motion commands is triggered during a machine state that prohibits movement, such as during tool change, manual mode, or when axis servo is off. The CNC cannot execute the interrupt routine because critical conditions for motion are not met.

FANUCProgram/G-codeAdvanced45-90 minutes

1101

Fanuc Alarm 1101 - ILLEGAL CNC STATEMENT IRT

MACRO ALARM 1101

Root Cause Summary

Alarm 1101 occurs when a custom macro interrupt (M96/M98 or G10 L1) containing motion commands is triggered during a machine state that prohibits movement, such as during tool change, manual mode, or when axis servo is off. The CNC cannot execute the interrupt routine because critical conditions for motion are not met.

Causes and Fixes

1
Navigate to SYSTEM > PARAM and check Parameter 6071 (Interrupt Type Setting). Verify bit 0 (M code interrupt enable) and bit 1 (macro interrupt type) are set correctly for your application. Typical setting is 1 for standard macro interrupts.
2
Check Parameter 6073 (M code number for interrupt). Confirm the M code number matches your ladder program interrupt signal (G0011.0-G0011.7) and does not conflict with standard M codes used during tool changes (M06, M60, etc.).
3
Review the macro interrupt program (O9001-O9009 typical) and verify motion commands (G00, G01, G02, G03) are not placed before checking machine state flags. Add conditional checks using system variables #3003 (mode status) and #3004 (emergency stop status).
4
If interrupt occurs during automatic operation, check Parameter 6072 (Interrupt Disable Conditions). Set bits to disable interrupts during inappropriate states: bit 0 (during reset), bit 1 (during alarm), bit 2 (during single block stop), bit 3 (during feed hold).
Modifying interrupt parameters requires careful testing to avoid disrupting existing macro interrupt functionality

DIY Feasiblehigh confidence

Call a technician if:

·Parameter corruption suspected
·Hardware interrupt signal issues
·Servo system faults during interrupt

Prevention

Always verify machine state before interrupt calls
Use non-movement commands in interrupt macros when possible
Implement proper interrupt timing with completion checks
Test interrupt macros in single block mode first

Common Mistakes

Calling interrupts immediately after M06
Using G-code moves in interrupt macros
Not checking machine state before interrupt execution
Ignoring feed hold status during interrupt calls

Related Alarms

1100 1102 1103 2010 2020

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