180

Access the part program and locate the line number referenced in the alarm display or history.

Identify the G31 skip function block and examine all commands on that line and surrounding lines for prohibited codes (G28, G29, canned cycles G73-G89, or multiple motion commands).

Remove or relocate the incompatible G-code commands to separate blocks before or after the G31 skip function.

Reset the alarm, restart the program from a safe position, and verify proper execution through the skip block in single block mode.

Ensure probe or skip signal is properly connected before testing G31 to prevent unexpected machine movement

Review the G31 block syntax ensuring it includes at least one axis movement command (X, Y, Z, etc.) and a valid feedrate (F word).

Verify that parameters 6200-6209 (skip function parameters) are correctly set for your machine configuration using the parameter screen.

Do not modify parameters without backing up current settings and consulting machine documentation

Check that the G31 command uses incremental (G91) or absolute (G90) mode consistently and that target positions are within machine travel limits.

Correct the G31 block formatting to include proper syntax: G31 X__ Y__ Z__ F__ and test in single block mode with dry run active.

Check if the G31 block contains macro variables (#1-#9999) and verify all variables are properly defined and assigned values before the skip function is called.

Review any calculations or conditional statements (IF/WHILE/GOTO) immediately preceding the G31 block for syntax errors or division by zero conditions.

Temporarily substitute actual numeric values for variables in the G31 block to isolate whether the variable value or syntax is causing the alarm.

Add variable value checks using DPRNT or alarm statements before the G31 block to verify variables contain valid position and feedrate data during execution.