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FANUC Controller
Program/G-code · Intermediate · 5-30 minutes
Fanuc 36 - Illegal argument
Alarm 036 ILLEGAL ARGUMENT occurs when the CNC control encounters a parameter, address, or value in the G-code program that is improperly formatted, out of acceptable range, or logically invalid for the commanded function. This is typically a syntax error where the control cannot parse or execute the argument as written in the active program block.
036
Fanuc 36 - Illegal argument
ILLEGAL ARGUMENT
Fanuc PS program alarm 36: ILLEGAL ARGUMENT. This alarm is triggered by an illegal or incorrectly formatted command in the part program, or a programming condition that the Fanuc control cannot execute.
Root Cause Summary
Alarm 036 ILLEGAL ARGUMENT occurs when the CNC control encounters a parameter, address, or value in the G-code program that is improperly formatted, out of acceptable range, or logically invalid for the commanded function. This is typically a syntax error where the control cannot parse or execute the argument as written in the active program block.
Safety
- Verify corrected program or parameters before resuming machining
Causes and Fixes
- 1
Identify the exact block number displayed with the alarm on the CNC screen and locate that line in the part program.
- 2
Check all numeric values in that block for proper formatting: verify decimal points are correct, no letters mixed with numbers (except E for exponential notation if supported), and no special characters.
- 3
Compare the numeric values against the machine's travel limits and parameter settings (maximum feedrate, spindle speed limits, coordinate system limits) found in the machine parameter and specification documentation.
- 4
Correct the out-of-range or malformed value, re-verify the program syntax, and reset the alarm before restarting the program.
Ensure machine coordinate limits are not exceeded to prevent potential crash conditions.
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