Fanuc Keep Relay Parameters Exclusive [cracked] Here
Keep Relays (K-parameters) are a specialized type of internal memory bit used within the Programmable Machine Control (PMC)
to enable or disable specific machine options, logic flows, or hardware configurations without rewriting the PLC ladder. Key Characteristics of Exclusive Keep Relays Non-volatile Storage:
Unlike standard relays, Keep Relays "keep" their state (1 or 0) even after the machine is powered off. Bit-Level Logic:
They are accessed in the PMC as bits (e.g., K0.0 through K99.7). Option Locking:
OEMs often use specific Keep Relays as "exclusive" switches to toggle between different machine features—such as enabling a 4th axis, switching between manual and automatic tool measurement, or locking out certain door interlocks for maintenance. Safety & Interlocks:
Because they are "exclusive," setting one bit often logically inhibits another operation in the ladder to prevent mechanical collisions or unsafe conditions. How to Access and Modify 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
(ON). The machine will trigger a non-critical alarm; this is normal MachineMetrics Navigate to PMC Maintenance: function key. soft key, followed by Modify the Bit:
Use the cursor to highlight the specific Keep Relay address (e.g., K0005).
Enter the binary value for the specific bit you wish to change (remembering that bit 0 is on the far right and bit 7 is on the far left). Disable PWE:
Return to the Setting screen and change "PARAMETER WRITE" back to
Always consult your machine's original documentation or the OEM ladder diagram before changing Keep Relays, as they are specific to each machine builder and changing the wrong bit can disable critical safety features or machine functions. common K-relay addresses used by specific manufacturers like Haas or Mori Seiki? fanuc keep relay parameters exclusive
In the context of (Programmable Machine Controller) maintenance, Keep Relay parameters
act as non-volatile memory bits that retain their state even after power is turned off. These are primarily used by machine tool builders to enable or disable specific machine options, such as chip conveyors or tool management features. "exclusive"
in the context of these parameters typically refers to two scenarios: exclusive-OR (XOR) logic applied to PMC addresses or exclusive access/protection of parameters. 1. Functional Roles of Keep Relays
Keep relays (K-parameters) serve several critical roles in machine automation and maintenance: Feature Toggling: Enabling or disabling optional equipment like a chip conveyor high-pressure coolant Bypassing Sensors:
Temporarily shielding external alarms or bypassing faulty sensor inputs (e.g., conveyor rotation detection) to keep the machine running. Safety & Interlocks: Managing interlocks such as chuck clamp signals or ATC (Automatic Tool Changer) safety conditions. System Configuration:
Certain "System K" parameters (like K900+) are reserved for internal CNC functions and protected against general modification. 2. Exclusive Logic and Protection
The concept of "exclusive" keep relay parameters appears in technical maintenance documentation in two ways: A. Exclusive-OR (XOR) Operations
In PMC ladder logic maintenance, specific addresses may be processed using Exclusive-OR
operations. For example, a diagnostic address (like R90) might be XOR'ed with a decimal value (like 255) to flip all bits for specific logic evaluations. B. Exclusive Protection (Parameter Hiding)
Modern FANUC controls allow machine builders to set keep relays to "exclusive" or protected states to prevent unauthorized changes: K902.6 / K19.6 (HIDE PMC PARAM):
When set to 1, this "hides" the Timer, Counter, Keep Relay, and Data Table screens entirely. K902.7 / K19.7 (PROTECT PMC PARAM): Keep Relays (K-parameters) are a specialized type of
When set to 1, it becomes impossible to modify these screens, even if they are visible. 3. How to Access and Modify Keep Relays
To change a keep relay (e.g., turning a feature ON or OFF), follow these standard steps: How to Enable Parameter Write Enable (PWE) on a Fanuc CNC
In Fanuc CNC systems, Keep Relays (often referred to as K parameters or K addresses) serve as critical software switches within the Programmable Machine Control (PMC). Unlike standard temporary relays, these are "holding-type" devices stored in non-volatile memory, meaning they retain their state (on or off) even after the machine is powered down. The Role of Keep Relays
Keep relays act as the interface between the machine's hardware and the PLC ladder logic. They are primarily used by Machine Tool Builders (MTBs) to define how a specific machine should behave without requiring a rewrite of the entire ladder program. Common uses include:
Feature Management: Enabling or disabling hardware options like chip conveyors, coolant systems, or specific interlocks.
Maintenance & Debugging: Bypassing faulty sensors (such as a broken conveyor rotation sensor) to keep the machine running during diagnostics.
Process Flags: Tracking ongoing operations, such as signaling that a tool change is in progress so the machine can recover safely after a power failure. Structure and Addressing
Keep relays are organized in an 8-bit octal system, where each address (e.g., K0) contains eight individual bits labeled 0 through 7.
User Keep Relays (K0–K99): Typically reserved for the machine builder to customize operations like chuck clamping or turret rotation.
System Keep Relays (K900–K999): Control internal CNC system functions, such as safety circuit interfaces or ladder editing modes. These are often hidden and only become visible under specific conditions, such as when the emergency stop is pressed. How to Modify Keep Relays
Changing a keep relay is a standard maintenance task, but it requires specific steps to unlock the system's "write" permissions: Overview: Making FANUC Keep-Relay Parameters Exclusive 2
Enable Parameter Write: Switch the machine to MDI mode, go to the Setting screen, and change "Parameter Write" from 0 to 1.
Navigate to PMC Maintenance: Press the System key, then use the right-hand arrow soft keys to find PMC Maintenance followed by the Keep Relay soft key.
Locate the Bit: Cursor to the desired address (e.g., K5.4). Remember that bits are counted from right to left (0 is the furthest right).
Input Value: Enter 1 to enable or 0 to disable the function.
Secure the System: Once finished, return to the Setting screen and change "Parameter Write" back to 0 to prevent accidental changes. Implementation Variability
It is vital to note that keep relay assignments are exclusive to each machine builder. For instance, K10.7 might control an air blast on one machine but handle a pallet changer on another. Operators should always consult the specific ladder diagram documentation or the machine's manual before making adjustments. To help you with a specific setup,g., Mori Seiki, Doosan)?
Find the steps to bypass a specific alarm (e.g., door interlock or conveyor)?
Learn how to search the PMC ladder to identify an undocumented keep relay? Fanuc PMC - Keep Relays (K Parameter) Explained in English
Overview: Making FANUC Keep-Relay Parameters Exclusive
2. Warranty and Liability
If a service technician modifies an exclusive Keep Relay without authorization and the machine crashes a spindle or collides tools, the warranty becomes void. Machine builders protect these parameters to control their liability.
Strategic Exclusivity: Diagnosis and Security
From a maintenance perspective, Keep Relays offer an exclusive diagnostic benefit. Because they directly reflect the state of machine options and custom logic, a technician can quickly audit the machine’s configuration. For example, if a tool changer stalls, checking the relevant Keep Relay (e.g., "Arm cycle time enable") can reveal whether a custom timer has been disabled.
Conversely, their exclusivity creates a security boundary. Malicious or accidental modification of Keep Relays is one of the fastest ways to disable safety circuits. Hence, responsible machine manuals list Keep Relay changes as a "service-only" procedure, often requiring a manufacturer-provided unlock code. This elevates Keep Relays from mere parameters to controlled configuration assets.
3. Backup Complexity
While Keep Relays hold data without power, they are often excluded from standard SRAM backups unless specifically configured. When cloning a machine, failure to clear or set the correct Keep Relays can lead to configuration mismatches.
3. Change Control is Mandatory
Because Keep Relays bypass normal operator screens (most operators do not have access to the K parameter page), changes must be exclusive to maintenance personnel.
- Write a change log: Each K parameter modification should be recorded with date, reason, and old/new state.
- Back up the PMC: Always export the
.000(or.LAD) file before altering Keep Relays.