Fanuc Keep Relay Parameters Exclusive !exclusive! Link

If a keep relay refuses to change or reverts after a power cycle, it is often because:

Fanuc PMCs use several data areas to execute ladder programs:

These relays are used by machine tool builders (OEMs) to set specific functionality, machine options, and configuration toggles, such as: Enabling or disabling specific safety interlocks. Toggling between automatic and manual tool change modes. Activating peripheral equipment (conveyors, loaders).

Remember that when parameters are mutually exclusive, changing one bit may have a domino effect on the spindle, the tool magazine, or the coolant system. fanuc keep relay parameters exclusive

Keep relays are organized by address (e.g., K0, K1, K2) and then by individual bits (0 through 7).

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Configuring ATC (Automatic Tool Changer) or Turret behavior. Locating and Changing Keep Relay Parameters If a keep relay refuses to change or

Because changing Keep Relays directly alters the machine’s safety and operational logic, FANUC restricts modification behind a software lock called . Step 1: Enable Parameter Writing Press the OFFSET/SETTING hard key on the MDI panel. Press the SETTING softkey. Move the cursor to PARAMETER WRITE (PWE) . Change the value from 0 to 1 (Press 1 then INPUT ).

Input 1 and press . The control will display a non-critical "MDI PWE" alarm. This is normal. Step 2: Navigate to the PMC Keep Relays Press the SYSTEM function key.

Press the soft key (on newer controls, press [PMC MNT] or [PMCPRM] ). Select the [K-PARAM] or [KEEP-RELAY] soft key. Step 3: Edit the Binary Bits Share public link Configuring ATC (Automatic Tool Changer)

Modifying keep relays requires entering the PMC Maintenance screen. The machine must be in and parameters must be enabled. Enable Parameter Writing: Press the [OFFSET] button. Go to the [SETTING] screen.

Do not guess what a Keep Relay does. Press SYSTEM -> PMC -> LADDER and search for the K address. Trace the rung to see what contacts it activates and what addresses conflict with it.

Because keep relays directly alter machine logic, Fanuc locks parameter editing by default to prevent accidental modifications that could cause machine crashes or operator injury.

If the exclusive logic is already written into the PMC ladder and you simply need to toggle or verify the active parameters, follow these steps on your FANUC MDI panel: Press the OFFSET/SETTING hard key. Press the SETTING softkey.