PS124

Access the macro program in EDIT mode. Press PRGRM key, locate the O-number or subprogram containing macro variables (#1-#33 local, #100-#999 common). Review all IF statements for matching END statements.

Count IF-THEN occurrences and corresponding END statements. For nested IF blocks, each level requires its own END. Verify structure: IF[#1 EQ 1]THEN / (statements) / END. Check parameters 6001-6049 (macro variable settings) are enabled if macro appears inactive.

Add missing END statement(s) before program termination (M99 for subprogram or M30 for main). Ensure END placement is logically correct for the intended control flow structure.

Reset alarm with RESET key, perform dry run test (SINGLE BLOCK + DRY RUN active). Monitor CURRENT screen (PRGRM > CURRENT) to verify macro execution path follows intended logic without PS124 reoccurrence.

In EDIT mode, search macro program for all WHILE statements (format: WHILE[#variable comparison]DO). Each WHILE-DO requires exactly one END statement to close the loop structure.

Verify loop termination logic. WHILE[#100 LT 10]DO / #100=#100+1 / (loop statements) / END. Check that END statement exists before program exit or next major control structure (IF, another WHILE).

Infinite loops can occur if loop counter logic is incorrect even with proper END statements. Verify increment/decrement logic.

For nested WHILE loops, ensure each level has its own END. Outer WHILE-DO-END must fully contain inner WHILE-DO-END structure. Use indentation in program editor to visualize nesting levels.

Add missing END statement(s) at appropriate loop closure points. Reset alarm and test with SINGLE BLOCK mode active, monitoring macro variable values via SYSTEM > MACRO > VARIABLE display to confirm loop execution and termination.

Locate all DO loop statements in macro program via EDIT mode. Format is DO#variable=start_value,end_value,increment_value. Each DO requires one END statement to complete the structure.

Check for premature program termination or branching (GOTO statements) that may skip over END statement. Verify END is reachable in all execution paths and appears before M99/M30 or subsequent control structures.

Add missing END statement after all loop body statements. Verify parameter 6071 (macro statement format) is set correctly (typically 0 for standard Fanuc macro B format). Check bit 0 of parameter 3203 (macro executor enable) is set to 1.

Clear PS124 alarm with RESET, test program execution in SINGLE BLOCK with Z-axis cancel active for safety. Verify loop executes correct number of iterations by monitoring current block display and macro variable values.