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Access parameter settings and check parameter 5501 (cylindrical interpolation radius). Verify it contains a non-zero positive value matching your workpiece radius.

If parameter 5501 is zero, enter the correct radius value in millimeters or inches (depending on system units). Typical values range from 10 to 500mm depending on application.

Parameter write-enable switch must be ON. Record original value before changes.

Verify parameter 5511 (cylindrical interpolation axis selection) is correctly set to specify which axis represents the circumferential direction (typically C-axis).

Cycle power to the CNC control after parameter changes, then retest the program from a safe position using single block mode.

Ensure tool is clear of workpiece before testing.

Review the G07.1 activation line in the program. Verify format is correct: G07.1 C___ (where C specifies the circumferential axis). Check for missing or extra address codes.

Examine the block immediately before the alarm occurs. Ensure no conflicting G-codes (like G02/G03 with invalid parameters) or zero-value radius commands (R0) are programmed.

Verify that the programmed C-axis moves create valid tool paths. Calculate expected radius from coordinates to confirm non-zero values. Check for I, J, K arc center specifications that may result in zero radius.

Test with a proven sample program using G07.1 from the Fanuc manual or a known-good backup. If sample works, compare syntax differences with the failing program.

Check if macro variables (e.g., #variables) are used to define radius or related dimensions. Monitor variable values using the macro variable display during program execution to identify zero assignments.

Verify work coordinate system offsets (G54-G59) are correctly set. Incorrect offsets may cause the control to calculate tool position at spindle centerline (radius=0).

If using fixture offsets or external measurements, verify the actual workpiece is loaded and positioned correctly. Missing workpiece may cause measurement systems to return zero radius.

Confirm workpiece is securely mounted before running program.

Review any custom macro programs (O9xxx series) that may calculate or modify radius values. Add debug output statements to track calculation flow and identify where zero values originate.