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FANUC Controller
Program/G-code · Intermediate · 30-60 minutes
Fanuc Alarm 065 - ILLEGAL COMMAND IN G71-G73
Fanuc Alarm 065 occurs when the first block of a shape definition program for canned cycles G70 (Finishing Cycle), G71 (Turning/Roughing Cycle), G72 (Facing Cycle), or G73 (Pattern Repeating Cycle) does not begin with G00 (Rapid Positioning) or G01 (Linear Interpolation). The system requires an explicit motion command to establish the starting point and direction of the cutting path definition.
065
Fanuc Alarm 065 - ILLEGAL COMMAND IN G71-G73
M Code Number Error
Fanuc alarm 065: M Code Number Error. This alarm indicates a fault condition detected by the Fanuc control. Refer to the alarm number and name to identify the specific system or function involved.
Root Cause Summary
Fanuc Alarm 065 occurs when the first block of a shape definition program for canned cycles G70 (Finishing Cycle), G71 (Turning/Roughing Cycle), G72 (Facing Cycle), or G73 (Pattern Repeating Cycle) does not begin with G00 (Rapid Positioning) or G01 (Linear Interpolation). The system requires an explicit motion command to establish the starting point and direction of the cutting path definition.
Safety
- Verify M code function before running program to prevent unexpected machine behavior
- Before modifying any machine parameters or ladder logic, back up the existing configuration to prevent data loss.
- Be aware of potential machine movements when executing M-codes. Ensure the work area is clear of obstructions and personnel.
- Some M-codes control potentially hazardous functions (e.g., spindle start, coolant activation). Verify the intended function before executing the code.
- Electrical hazards may be present when troubleshooting machine components. Disconnect power before working on electrical components, and follow proper lockout/tagout procedures.
- Mechanical hazards may be present when troubleshooting machine components. Use caution when working around moving parts, and wear appropriate personal protective equipment (PPE).
- Before performing any steps, ensure the machine is powered off or in a safe state to prevent accidents.
Causes and Fixes
- 1
Review the NC program at the alarmed line. Identify the G71, G72, or G73 block and locate the sequence number (N-number) referenced as the start of the shape program (P parameter).
- 2
Verify the first block of the shape program (immediately after the referenced sequence number) begins with G00 or G01. Check for G02, G03, G04, or other commands that are invalid as first motion commands.
- 3
Correct the program by changing the first motion block to G00 (for rapid approach) or G01 (for linear cutting motion) with appropriate X and Z coordinates defining the shape start point.
- 4
Reset the alarm using the RESET key, return to the program start or safe block, and execute the corrected program in single block mode to verify proper cycle execution.
Call a technician if:
- ·Parameter corruption suspected
- ·Multiple related alarms occurring
- ·Shape program syntax appears correct but alarm persists
Prevention
- Always start shape programs with G00 or G01
- Use consistent sequence numbering for P/Q references
- Validate canned cycle syntax before program release
- Maintain proper G-code modal states in shape programs
Common Mistakes
- Starting shape programs with G02/G03 arcs
- Incorrect P/Q sequence number references
- Missing coordinate data with G00/G01 commands
- Using G04 dwell as first command in shape program
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