Fanuc Parameter 8901 Better Here

Fanuc Parameter 8901: In-Depth Technical Explanation

1. What is Parameter 8901?

Parameter 8901 (sometimes listed as bit parameters 8901.0 through 8901.7) controls the Grid Shift Reference Point Return method and the Dogless Reference Return behavior on many Fanuc CNC controls, particularly Series 0i, 16i/18i/21i, 30i, and 31i.

Warnings

• Do not change 8901 if you don't have a rotary axis configured
• Changing this parameter may require power-off/on
• Can affect absolute position recovery
• Some machines lock this parameter with a password

Date: October 26, 2023 Subject: Optimization of Parameter 8901 (High-Speed High-Precision Machining) System: FANUC Series 30i/31i/32i/0i Model D (and equivalent)

Action Step: Go to your Fanuc control. Press SYSTEM, then PARAM. Search for 8901. If it says "0" or "1," you are leaving quality on the table. Write down your current value, change it to 2, run a test arc, and decide for yourself. fanuc parameter 8901 better

Note: A "P/S 100" alarm will appear; this is normal and indicates the control is in write-enable mode. 2. Locate and Modify Parameter 8901

4. Pros and Cons

| Pros | Cons | | :--- | :--- | | Safety: Reduces the risk of crashes caused by assumed coordinate positions. | Confusion for New Operators: If an operator intentionally wants to clear the offset state via Reset, this parameter prevents it, requiring a manual G53 or mode change. | | Efficiency: Faster recovery from program stops; no need to re-reference the coordinate system. | Global Effect: It applies globally to the control, so it cannot be toggled per-program easily. | | Data Security: Prevents accidental wiping of G54-G59 values during routine resets. | | Fanuc Parameter 8901: In-Depth Technical Explanation 1

Do not let a legacy default setting sabotage your productivity. Talk to your lead machinist, review a test machine, and change Parameter 8901 to 1. In one work shift, you will wonder why you didn't make it better years ago.

1 System fan, 701 alarm, 8901#0 parameter is changed to 1 to temporarily shield the alarm (OIC system); www.jidemachinery.com Common CNC Machine Parameter Guide - ALLPCB Do not change 8901 if you don't have

However, strict documentation should be provided to operators. If a setup person attempts to "clear the machine" by pressing Reset multiple times, they may be confused why the coordinate system hasn't cleared to Machine Zero. This is a minor training hurdle compared to the safety benefits provided.