Fanuc 9900 Parameter List Access

Understanding Fanuc 9900 Series Option Parameters The Fanuc 9900 series parameters are designated as Option Parameters on modern Fanuc CNC controls, such as the 16i, 18i, 21i, and 0i series. Unlike standard machining parameters, these bits enable or disable core system functions like additional memory, high-speed machining, and specialized canned cycles. Key Functionality Highlights

The 9900 range typically controls high-level system configurations. Common options found in this range include:

Memory Expansion: Parameters like 9921 control part program storage capacity, ranging from 40m to 640m.

Programming Features: Enabling Helical Interpolation (9925.0) or Custom Macro B (9926.7).

Axis & Spindle Control: Managing Spindle Synchronization (9926.1) or simultaneous 4-axis control (9926.5).

Tooling Options: Expanding tool offset memory to 64 or 99 pairs (9926.3, 9926.4). Crucial Access Warning fanuc 9900 parameter list

Proceed with extreme caution. On controls manufactured after July 2006, Fanuc significantly restricted access to the 9900 series.

Visibility: These parameters often do not appear on the standard parameter screen and are instead hidden within a diagnostic screen.

Modification: You generally cannot change these manually. Enabling new options usually requires paying Fanuc for an "option file" that is loaded via memory card.

Risk: Incorrectly modifying these bits can cause fatal system errors, requiring a full memory clear and restoration from backups. Sample Parameter Bit List

Below is a selection of commonly cited 9900-series bits for the 16i/18i/21i controls: Parameter.Bit Description 9920.1 Tool offset input with G10 9920.5 Inch/Metric conversion 9922.2 Constant surface speed control 9922.6 Custom Macro A 9925.3 Look-ahead control (High-speed machining) 9926.7 External tool compensation 9937.4 Extra Macro Variables How to Check Your Current Options Understanding Fanuc 9900 Series Option Parameters The Fanuc

If your control allows viewing, you must first enable Parameter Write Enable (PWE): Set the machine to MDI Mode. Press the OFFSET/SETTING key.

Change PARAMETER WRITE from 0 to 1 (this will trigger an alarm, which is normal).

Navigate to the SYSTEM -> PARAMETER screen and search for 9900.

For a comprehensive official list, refer to the Fanuc Parameter Manual specific to your control model.

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1. Introduction

FANUC CNC systems utilize parameters to define machine behavior, from servo gain to I/O assignments. Parameters 9900–9999 are distinct: they are hardware and software configuration parameters set at the machine tool builder (MTB) level. Unauthorized or incorrect changes to these values can disable the CNC, corrupt the PMC (Programmable Machine Controller), or render the machine inoperable. List critical 9900-series parameters

This paper aims to:

• List critical 9900-series parameters.
• Describe their functions.
• Explain the password/PMC ladder security preventing access.
• Propose a safe modification protocol.

Why is the 9900 List "Hidden"?

Unlike other parameters, the 9900 series is not typically listed in the standard "Parameter Manual" provided by Fanuc. Instead, these settings are usually documented in the Machine Tool Builder’s Manual (e.g., Makino, Mori Seiki, Haas, etc.).

The reason for this secrecy is simple: Risk.

If you change a standard parameter incorrectly, you might get an alarm or a crash. If you change a 9900 parameter incorrectly, you can instantly disable the control, make the screen go blank, or wipe out critical system options. Because these parameters configure the core hardware communication, the control may not even know how to boot up properly if they are altered.

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How to Access the 9900 Parameters

On most modern Fanuc controls, the 9900 parameters are write-protected. To view or modify them, you generally need to follow this procedure:

1. Enter MDI Mode.
2. Enable Parameter Write:
   • Go to the SETTING screen.
   • Change PWE (Parameter Write Enable) to 1.
3. Unlock System Parameters:
   • Some controls require a specific key sequence or a "Keep Relay" (PMC K-Parameter) to be set to "1" to allow editing of system parameters.
   • Note: This differs by machine builder.
4. Navigate:
   • Press the SYSTEM button.
   • Type 9900 and press SEARCH.
   • If the screen shows "Parameter not found," the parameters may be hidden by a setting in the Keep Relays.

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