PS0116

Press RESET to clear the PS0116 alarm. Note the program line number (N-number) displayed with the alarm on the alarm screen.

Navigate to EDIT mode and locate the offending program line. Look for assignment statements like '#3001=100' or similar attempts to write to system variables in the #3000-#3999 range.

Review Fanuc macro variable specification (FANUC Series 30i/31i/32i-B OPERATOR'S MANUAL B-63944EN) to verify which system variables are read-only. Common read-only variables include #3001-#3006 (date/time), #3011-#3012 (timers), #3021-#3022 (power-on time).

Modify the program to either read the variable without assignment, or use a non-protected common variable (#100-#199, #500-#999) or macro variable to store calculated values instead of attempting to overwrite system variables.

Do not attempt to bypass this alarm by modifying system parameters. Read-only variables are protected for system integrity.

Press RESET and navigate to PROGRAM > CURRENT SCREEN to identify the active program and subprogram calling hierarchy at the time of alarm. Note O-number and sequence number.

If using C-Language Executor, check SYSTEM > C-EXE screen for active applications. Review application source code for any 'cnc_wrpmacro' or similar API calls attempting to write to protected variable ranges.

C-Language Executor applications must comply with variable access restrictions defined in FOCAS2/C-EXE library documentation.

Review macro program flow and verify all G65/G66 macro calls pass arguments correctly using local variables (#1-#33) or non-protected common variables. Check for inadvertent assignment to system variables within nested macros.

If the application requires system status information, modify code to read system variables into user-defined variables first, then manipulate those copies rather than attempting direct modification of protected system variables.

Press RESET to clear alarm. Navigate to SYSTEM > PMC > ALARM screen to check for related PMC alarms or error messages that may indicate PMC-initiated macro variable write attempt.

Access PMC ladder program: Press SYSTEM > PMC > LADDER DISPLAY. Search for WINDR (read) and WINDW (write) function blocks. Check address parameters to verify target macro variable numbers are not in protected ranges.

Modifications to PMC ladder require appropriate access level and PMC programming knowledge. Consult machine builder documentation.

Review M-code execution sequences and corresponding PMC ladder logic. Verify that any macro variable writes triggered by M-codes target user-defined variables (#100-#199, #500-#999) rather than system variables (#3000+).

If PMC window function must access system information, modify ladder to use WINDR (read-only) for system variables, then transfer values to writable common variables for further processing or display on operator panel.