Modifying underlying parameters requires entering the state. Follow these sequential instructions to complete the process smoothly: Step 1: Switch to MDI Mode PARAMETER MANUAL
Fan bearings dry out over years of multi-shift operation. Keep a spare Fanuc-certified internal fan assembly in your shop's inventory to quickly resolve faults without needing to alter system parameters.
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 0 0 0 0 0 0 0 Cursor to the furthest right digit ().
If your Fanuc drives are series Alpha i or earlier (without high-speed HRV control), Parameter 8901=2 can cause audible "squealing" or axis oscillation. The servo loop cannot keep up with the advanced look-ahead, leading to overcompensation. fanuc parameter 8901 better
The short answer is . Setting Parameter 8901 to a specific non-zero value is statistically better for modern high-speed machining, but only if you understand the trade-offs. This article will explain what 8901 does, why the default setting is outdated, and how optimizing it makes your machine better .
In the world of FANUC CNC controls (Series 0i, 30i, 31i, 35i, etc.), Parameter 8901 is a small but mighty binary switch. Officially titled its default setting works for 80% of users. But "better" is not a single setting—it is a strategy.
By changing parameter 8901, you can temporarily clear the 701 alarm. This allows the machine to run, assuming the fans are not critically necessary for that specific moment (e.g., in a well-ventilated, low-load scenario). 2. Time-Efficient Troubleshooting Modifying underlying parameters requires entering the state
serves as a diagnostic shield. Setting this specific bit to 1 commands the controller to suppress the active fan error, bypassing the hard interlock and allowing the machine to cycle even if a cooling fan is completely non-functional. Step-by-Step Configuration Strategy
: Mark the parameter change inside your machine logbook. Treat this override as a strict emergency tool limited to a single shift or a maximum runtime of 24 to 48 hours.
This bit determines whether the CNC monitors the cooling fans within the control unit. Bit 7 Bit 6 Bit 5 Bit 4
If the 701 alarm persists even after checking the fans, you likely have a faulty cabling issue or an amplifier malfunction, not a simple fan failure. Conclusion
: Setting bit 0 (the rightmost digit) of parameter 8901 to 1 disables the 701 alarm, allowing the controller to ignore a faulty fan.
“Better” also requires:
The benefits of this architecture are manifold: