Fanuc Keep Relay Parameters Exclusive -
Write any modified Keep Relay values on a label inside the electrical cabinet door. If the CNC memory ever wipes, future technicians will know exactly how the machine logic was customized.
When technicians blindly change Keep Relays without consulting the OEM manual, they risk corrupting the operational logic of the machine. The consequences fall into three main categories: Deadlocks (State Hang-ups)
These are reserved by FANUC for essential PMC and system-level functions, such as safety circuits, DCS (Dual Check Safety), or special NC functionalities. .
: Bypassing safety circuit interfaces or hiding specific system screens. Important Documentation
Ensuring a pallet cannot be unclamped manually if the machine is running in automatic cycle. fanuc keep relay parameters exclusive
The practice of using "Exclusive" Keep Relays (commonly utilizing the non-volatile K-parameters or specific D-Data addresses) is , but it is a "high-risk, high-reward" feature.
Input the new binary value ( 0 or 1 ) and press the key.
FANUC CNC systems use a built-in Programmable Machine Controller (PMC) to manage the interface between the CNC software and the physical machine tool hardware. Within the PMC, serve as critical non-volatile memory bits. These relays retain their state (0 or 1) even after the machine is powered down.
Keep relays can enable or disable external hardware like pallet changers (e.g., K15.0 on some RoboDrills) or chip conveyors without changing the ladder logic. Write any modified Keep Relay values on a
Keep relays are normally addressed on a bit level. For example, refers to the 3rd bit (bit 2) of Keep Relay byte 17. The machine's ladder logic references these bits directly—their state (0 or 1) tells the machine how to behave.
: Modifying turret rotation requirements (e.g., allowing rotation without requiring the X/Y axes to be at home) to reduce cycle time.
A common requirement in machine tool automation is creating "exclusive" logic using these keep relays. This article covers how to configure, modify, and utilize FANUC keep relay parameters when you need mutually exclusive operations. What are FANUC Keep Relays?
To view or change these parameters, follow this standard procedure on most Fanuc controls: Enable Parameter Write (PWE): function key. Set "PARAMETER WRITE" to The consequences fall into three main categories: Deadlocks
Activating both overrides safety matrices, blinding the CNC to physical door states. Internal Barfeeder Interface K12.4 External Robot Interface
: High-range addresses often reserved for internal Fanuc system functions. How to Access and Modify Keep Relays
To even reach the PMC maintenance screens on a standard FANUC, the operator must set to 1. This is usually done by switching to MDI mode and flipping a soft switch. Without PWE, the system treat all parameter changes as locked.
Keep Relay functions vary significantly between machine builders. A K10.2 enabling coolant-on in one machine might activate a part catcher solenoid in another machine. Refer to the builder's ladder diagram documentation for accurate information.
Move the cursor to the specific bit (0-7). Remember, bits read from right to left ( 76543210 ). Type 1 or 0 and press the softkey. Disable Parameter Write: Go back to the OFFSET/SETTING page. Change "PARAMETER WRITE" back to 0 . Press the RESET key to clear the system alarm.