Fanuc Ot 900 Parameter List

  • Fanuc 0T has several versions:

  • To view 900 parameters on Fanuc OT:

  • Some parameters are stored as decimal values — e.g., 901 = 64 means bit 6 = 1 (binary 01000000)

    • For over four decades, the FANUC Series 0-T (Model C, D, and later)—commonly known as the FANUC OT control—has been the backbone of CNC lathes worldwide. From Okuma to Mori Seiki, Hardinge to Haas’s early lathes, this control is legendary for its reliability. However, even the most robust systems encounter issues: mysterious alarms, sudden halts, or a machine that simply refuses to power up. fanuc ot 900 parameter list

    When standard troubleshooting fails, the 900 parameter list becomes your most powerful diagnostic tool.

    Unlike standard 000–899 parameters that control feedrates, axis assignment, and user preferences, the 900–999 range (often referred to as Fanuc OT 900 parameters) governs the hardware configuration, software options, and built-in PMC (Programmable Machine Controller) diagnostics. Modifying these incorrectly can crash your machine—but understanding them can resurrect a dead control.

    In this article, we will provide the definitive FANUC OT 900 parameter list, explain what each parameter does, how to view it, and how to safely use it for backup, recovery, and troubleshooting. Fanuc 0T has several versions:

    This helps the control identify the generation of the servo system.

    1. Never rely on screenshots alone. The Fanuc OT 900 parameter list varies by:

    2. Backup before editing.
    Old Fanuc OT controls have volatile CMOS batteries. Use the PUNCH function to output all parameters to a PC: To view 900 parameters on Fanuc OT:

    EDIT mode → PUNCH → ALL PARAMETERS → EXEC

    Save the file. Specifically, save the 900 range (N900–N999).

    3. Do not "experiment" with 908 and 909.
    Setting 908 incorrectly can cause a "System HALT" requiring a ROM replacement. Setting 909 without the proper option key may lock the control permanently.

    4. Understand the "Parameter Number Changed" alarm.
    If you change a 900 parameter and get a "P/S 000" alarm with "PLEASE TURN OFF POWER," you must cycle the control fully. Some 900 bits require a cold start.

    5. Legal note:
    Enabling an option via the 900 parameter list that you did not purchase may violate your license agreement with Fanuc. However, if your machine label shows "Macro B included" but it’s disabled, you have every right to re-enable it.