To help narrow down the root cause of your 7115 error, please let me know:

At its core, the 7115 alarm is a feedback loop failure. The CNC controller sends a command to the Fanuc servo drive, which in turn moves the motor. When the actual position reported by the encoder differs too significantly from the commanded position—often due to mechanical resistance or electrical glitches—the system triggers the 7115 code to prevent damage. Primary Causes

(often Izumi brand) located in the electrical cabinet. Even if they show 24V on a multimeter, they may be failing under load or causing ripple issues. Contactor Issues : The alarm can be triggered by faulty hi/lo spindle contactors . Inspect these for mechanical binding or burnt contacts. Feedback/Resolver Errors

Check (Flexible Feed Gear ratios). Ensure these numbers accurately match the mechanical pitch of your ball screw and the resolution specification of your encoder. Step 3: Inspect the Physical Axis and Lubrication

Access the system boot screen (holding the two rightmost softkeys during power-on).

The Fanuc 7115 alarm is related to the program number (PGM NO.) not being ready or not found. Here's a breakdown:

Navigate to . Look for diagnostic address DGN 300 or 400 (model dependent). These bits will tell you where the I/O link failed.

The majority of electrical faults are connection issues. Once the machine is safe to work on, visually inspect all the cables associated with the alarming axis. This includes the thick motor power cables, the thinner encoder feedback cables, and any connectors on the amplifier itself. Look for any signs of damage, looseness, or corrosion.

Prevents unexpected downtime and loss of machine reference points. Check Diagnostic Screen

7115 Alarm Message: OVERSPeed (or related parameter error) Applicable Systems: Fanuc Series 16i/18i/21i, 16/18/21, 0i, and 30i Series controls.

Does it happen when ? (Likely a macro variable or parameter conflict).

| Bit | Function | Recommended Value | | :--- | :--- | :--- | | | Reference point return direction check | 1 (Skip check – default for most machines) | | | | 0 (Check enabled – more strict, may cause 7115) |

The FANUC 7115 alarm is a gatekeeper error. It shuts down the machine not because of a mechanical crash, but because the digital nervous system (the PMC and I/O Link) has detected a fatal inconsistency. It is intimidating, but it is almost always solvable with methodical troubleshooting.

If the alarm is accompanied by "AL-15," it specifically points to a switch control failure, suggesting the amplifier itself or the contactor circuit is the bottleneck. How to Reset the 7115 Alarm