Based on technical documentation, here is a snapshot of what these bits actually control: Description Functionality Unlocked CANNED CYCLE Enables standard G-code cycles like G81/G83. 900 G10 PROGRAM INPUT Allows software to update offsets automatically. 900 INCH / METRIC Toggle between imperial and metric measurement systems. 901 TAPE MEMORY Controls memory capacity (from 20M to 320M). 901 CHAMFER/RADIUS Enables corner rounding/chamfering G-codes. 902 CONSTANT SURFACE Allows the spindle to adjust speed based on diameter. 902 CUSTOM MACRO A Unlocks the ability to use variables and logic. 903 Enables the dynamic buttons below the CRT screen. 904 Changes the system text (Japanese, German, Spanish, etc.). How to "Unlock" These Settings
Do this today if you operate an old FANUC OT lathe:
When he hit = 10000001 (binary), that re-enabled the PMC’s custom ladder. When he set 910 bit 6 = 1, rigid tapping came back. When he set 932 bit 0 = 1, the fourth axis (which Diego had forgotten existed) was recognized. fanuc ot 900 parameter list
He powered off. Counted ten seconds. Powered on.
If your machine battery fails, it is possible to lose these 900-series parameters, rendering the machine incapable of using functions it previously had. Based on technical documentation, here is a snapshot
Set (binary) or add 16 to existing value if using decimal.
Spindle synchronous control (useful for live tooling/sub-spindles). Bit 5 (CSR): Corner shear speed control. Parameter 903 Bit 0 (SHP): Enables polygon turning options. 901 TAPE MEMORY Controls memory capacity (from 20M to 320M)
Note: The exact map depends on the FANUC OT ROM version (A16B-2200, A16B-2300, etc.). Below is the most common standard for OT-C and OT-D. Parameters are usually displayed in binary (8 bits) from bit 7 (left) to bit 0 (right).
Always, always , use the parameter list that came from your machine's builder. The following is a guide to help you decode what the bits in your list might mean.