The ladder logic file stored in the FANUC’s flash ROM or SRAM can become corrupted due to electrical noise, a dying battery, or a bad firmware update. When the CNC reads the ladder at boot-up or during runtime, it detects an invalid instruction or a missing END statement, triggering alarm 7115.
| Method | Action | Permanence | | :--- | :--- | :--- | | | Adjust parameter 1006#5 to match the machine’s physical reference return direction. | Permanent fix | | 2 | Move the axis manually to a safe position away from decel dog, then re-do reference return. | Temporary workaround | | 3 | Set 3004#5 = 1 to disable direction checking (most common solution for older machines). | Acceptable permanent if hardware correct | | 4 | Adjust or replace the deceleration dog or sensor if stuck or incorrectly positioned. | Permanent fix | | 5 | Change the *DECX signal logic in PMC or correct wiring if inverted. | Permanent fix | fanuc 7115 alarm
Common Causes