Fanuc Keep Relay Parameters Exclusive 🎯

In the context of (Programmable Machine Controller) maintenance, Keep Relay parameters

Use the arrow keys or type the specific K-address (e.g., K12 ) and press . Cursor over to the specific bit you need to change. Type 1 or 0 and press the [INPUT] key.

Some Keep Relays are exclusively "write-once" or "latching." For example, a Keep Relay that enables a paid option (like high-speed machining) may be set to 1 by an OEM field engineer and then permanently locked. Even if you try to change it back to 0 , the ladder logic will ignore the change due to a memory-protect key or a secondary hardware dongle. fanuc keep relay parameters exclusive

In the world of FANUC CNC controls (Series 0i, 31i, 35i, etc.), Keep Relays (often referred to as or K addresses ) are the unsung heroes of machine configuration. Unlike common system parameters that adjust servo loops or axis scaling, Keep Relays are discrete, bit-level switches that dictate machine-specific logic behavior.

Do you have a specific Fanuc Keep Relay challenge on your shop floor? Consult your machine builder’s documentation or a certified Fanuc integrator before making changes. Some Keep Relays are exclusively "write-once" or "latching

To make two keep relays exclusive, you must configure them as interlocking contacts within your FANUC PMC ladder diagram. The Hardwired Logic Approach

The technician guesses the issue, replaces a $1,200 ATC motor, and wastes 4 hours. No change. Unlike common system parameters that adjust servo loops

This is the classic symptom of a .

FANUC CNC systems rely on a Programmable Machine Controller (PMC) to manage communication between the CNC software and the physical machine hardware. Within the PMC, serve as non-volatile memory bits that retain their status (0 or 1) even after the machine is powered down.

FANUC provides the underlying hardware control, but the Machine Tool Builder writes the specific Keep Relay definitions. Always refer to the original machine manual's "PMC Parameter" appendix before making changes.

Prior to changing any exclusive bit, perform a full SRAM or PMC data backup to a USB drive or memory card. If an exclusive bit conflict locks up the PMC logic, you can easily restore the working baseline. Document the Original State