Fanuc Keep Relay Parameters Exclusive [2021]
Because they do not reset, a mistake made in a K-relay will persist until manually changed back, even if the machine is turned off. Conclusion
On a Doosan 2600 SY II lathe, the keep relay K25.1 (bit 1 of Keep Relay 25) was changed from 0 to 1. This single bit change immediately enabled M‑code M516 to function correctly.
By understanding how to properly read and modify , you can significantly reduce downtime and customize machine performance to meet specific production requirements. If you're interested, I can: fanuc keep relay parameters exclusive
The keyword "exclusive" in the context of FANUC keep relays refers to a critical distinction between and system-reserved exclusive parameters .
Keep Relays (K Parameters) are non-volatile internal relays within the Programmable Machine Control (PMC) that retain their state (0 or 1) even after the machine is powered down. They are primarily used by Machine Tool Builders (MTBs) to toggle specific options, manage maintenance modes, or bypass safety interlocks without rewriting the PLC ladder logic. Accessing and Modifying Keep Relays Because they do not reset, a mistake made
Certain critical K-parameters are tied directly to FANUC core firmware options. Modifying an exclusive option bit without matching changes to its corresponding paired bit will result in systemic initialization errors or state conflicts. Step-by-Step Guide: Accessing and Modifying Keep Relays
A: No, Keep Relays cannot be changed via G‑code commands such as G10. Parameter settings (G10) can modify CNC parameters but not PMC parameters. Keep Relay changes require manual intervention through the system interface or custom ladder logic. By understanding how to properly read and modify
When auditing or changing FANUC keep relay configurations, follow these rigorous industry standards:
Because keep relays are largely customized by the Machine Tool Builder (MTB), the exact functions of K900 through K999 (and user-defined K relays) differ drastically from builder to builder. Always reference the electrical or maintenance manual specific to your machine's serial number. Best Practices & Safety
Keep Relays are used to toggle machine options and control behavioral logic without changing the core ladder program.
Example: K928.7 and K929.0 are used to configure safe-state interfaces. B. User Keep Relays (K0–K899)