PS126

Press EDIT mode, navigate to the program causing the alarm and display the full macro program on screen. Use the search function to locate all DO statements and their corresponding END statements.

Verify each DO loop has exactly one matching END statement. Count nested levels - DO1/END1, DO2/END2, DO3/END3. Ensure DO numbers increment sequentially for nested loops and each END appears after its corresponding DO.

Check parameter 6010 (Macro Executor) is set correctly (typically bit 0=1 for macro enable). Navigate to SYSTEM > PARAM > search 6010 to verify macro functionality is enabled.

Correct the program structure by adding missing END statements or removing orphaned DO/END statements. Reset the alarm with RESET button and test the corrected program in single block mode.

Ensure machine is in a safe position before testing macro programs as syntax errors may cause unexpected motion.

Review the macro program and count the maximum nesting depth by identifying the deepest DO statement. Look for DO1 containing DO2 containing DO3 containing DO4 patterns.

Restructure the program logic to reduce nesting depth. Consider breaking complex nested loops into separate macro subprograms called with G65 or M98, or use GOTO statements to flatten the control structure.

Verify the nesting limit for your specific control series by checking the programming manual. Navigate to SYSTEM > DIAGN and check diagnostic 300-303 for macro executor status if available on your control.

After restructuring, clear the alarm with RESET and validate the modified program. Monitor diagnostic screens during execution to ensure proper macro processing.

Search the macro program for all CONTINUE and BREAK statements. Verify each references a valid DO loop number that exists in the current scope (e.g., CONTINUE2 must be inside a DO2-END2 block).

Ensure CONTINUE/BREAK statements only reference loop numbers from 1 to 3 and that the referenced loop is actually active at that point in program execution. Check for typos in loop number references.

Navigate to SYSTEM > PARAM and check parameter 3202 bit 6 (if available on 0i-F/30i/31i/32i series) which may affect macro statement processing. Consult parameter manual for your specific control version.

Correct invalid loop number references in CONTINUE/BREAK statements to match active DO loop numbers. Press RESET to clear PS126 and execute the program in single block to verify correct loop control flow.