Fanuc Alarm 4: ADDRESS NOT FOUND

Fanuc Alarm 4: ADDRESS NOT FOUND

Fanuc Control Model: Series 0i, 16i, 18i, 21i, 30i, 31i, 32i

Fanuc Alarm 4 (PS0004) is a Program/Editing alarm that occurs when an address letter (such as G, M, X, Z, or F) is missing required numerical data, or when a number is entered without a leading address letter. Follow this troubleshooting guide to resolve the issue quickly.

Official Alarm Description

A numeral or the sign “ – ” was input without an address at the beginning of a block. Modify the program.

Common Causes

This alarm is typically triggered by simple syntax or typing errors in the G-code program:

• Missing Address Letter: Typing a numerical value without specifying its corresponding letter (e.g., entering 100.0 instead of X100.0).

• Standalone Minus Sign: Accidentally inserting a minus sign (-) without an address or number attached to it.

• Incorrect Block Formatting: Leaving an incomplete command or empty address at the end of a G-code line.

• Typo in Custom Macro: Missing an address assignment when defining macro variables or program calls.

Step-by-Step Troubleshooting & Solution

Follow these steps to clear Alarm 4 and resume machine operation:

1. Switch to EDIT Mode: Turn the mode selector key on the CNC control panel to EDIT or MDI mode.

2. Locate the Faulty Line: Look at the screen cursor; it will highlight the exact block (line) of G-code where the error occurred.

3. Inspect the Code Syntax: Carefully check all axis positions (X, Y, Z), feedrates (F), and function commands (G, M) to ensure every number has a valid preceding letter.

4. Correct the Entry: Use the MDI keypad to delete stray characters, add the missing address letter, and press ALTER to update the line.

5. Clear the Alarm: Press the RESET key on the control panel. The alarm status will clear immediately.

G-Code Example (Correct vs Incorrect)

Incorrect Code: G01 50.0 F200 

Correct Code: G01 X50.0 F200 

Frequently Asked Questions (FAQs)

Q1: Does Fanuc Alarm 4 cause any physical damage to the CNC machine?

No. It is a software protection alarm that prevents the machine from executing incomplete or corrupted program blocks.

Q2: Do I need to restart the CNC machine to clear Alarm 4?

No, a power reboot is not required. Simply correct the missing address in EDIT mode and press the RESET button.