What causes FANUC alarm 062?

Specifying a zero or negative value for the depth of cut in a G71 or G72 multiple repetitive canned rough-cutting cycle. Incorrect programming of the G71 or G72 cycle parameters. Syntax errors in the G-code program.

How do I fix FANUC alarm 062?

1. Carefully review the G71 or G72 cycle block in the program and ensure the depth of cut parameter is a positive value. 2. Check for any other programming errors or typos in the G-code that may be causing the issue. 3. Simulate the program in the Fanuc control's built-in program verification mode to identify any other potential syntax or logic errors. 4. If the issue persists, consult the Fanuc programming manual for the correct syntax and parameters required for the G71 and G72 cycles. 5. Consider breaking down the roughing operation into multiple passes with smaller depths of cut to avoid this alarm. 6. As a last resort, modify the program to use an alternative roughing cycle, such as G70, that may be less sensitive to the depth of cut parameter.

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FANUC Controller

Program/G-code · Intermediate · 30-60 minutes

Alarm 062

Fanuc Alarm 062 - ILLEGAL COMMAND IN G71-G76

Fanuc Alarm 062 occurs when an illegal command is programmed within the G71-G76 rough cutting canned cycles. Most commonly, this is caused by programming a zero, negative, or missing depth of cut value (d parameter in G71/G72), or improper retract/finishing allowances that violate the cycle logic. The CNC detects these invalid parameters during program execution or background edit check.

FANUCProgram/G-codeIntermediate30-60 minutes

062

Fanuc Alarm 062 - ILLEGAL COMMAND IN G71-G76

FANUC ALARM 62

Root Cause Summary

Fanuc Alarm 062 occurs when an illegal command is programmed within the G71-G76 rough cutting canned cycles. Most commonly, this is caused by programming a zero, negative, or missing depth of cut value (d parameter in G71/G72), or improper retract/finishing allowances that violate the cycle logic. The CNC detects these invalid parameters during program execution or background edit check.

Causes and Fixes

1
Review the G71 or G72 block in your program. Verify the 'd' parameter (depth of cut per pass) is programmed with a positive value greater than zero (e.g., G71 U2.0 R1.0 P10 Q20 X0.5 Z0.2 D2000 F0.2 where D is in microns or D2.0 in mm depending on parameter 3460).
2
Check parameter 3460 (I-type cutting cycle unit) to confirm units. If bit 0=0, depth of cut is in microns; if bit 0=1, depth of cut is in mm. Ensure your programmed 'd' value matches the expected unit system.
3
Use the EDIT or PROGRAM screen to cursor to the exact G71/G72 block shown in the alarm position display. Verify all required address codes (U/W for G71, W/U for G72, P, Q, D or d) are present with valid positive values.
4
Correct the 'd' or 'D' parameter to a positive value appropriate for your cutting conditions. Typical values range from 0.5mm to 5.0mm for mm-based systems or 500 to 5000 for micron-based systems. Reset alarm with RESET key and restart cycle.

DIY Feasiblehigh confidence

Call a technician if:

·Memory diagnostic errors persist
·Parameter corruption suspected
·Multiple program integrity issues

Prevention

Always validate G71/G72 parameters before cycle start
Use program verification tools
Implement macro variable bounds checking
Regular program backup procedures

Common Mistakes

Programming D parameter as absolute instead of incremental
Forgetting decimal point in small depth values
Using undefined macro variables
Copy-paste errors from different cycle types

Related Alarms

061 063 064 010

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