Fanuc Keep Relay Parameters Exclusive [work] -

Title: The Guardians of Automation: The Criticality and Application of FANUC Keep Relay Parameters

In Fanuc CNC systems, Keep Relays (K-parameters) are software-based latching relays within the Programmable Machine Control (PMC) that maintain their state (ON or OFF) even after the power is cycled. These parameters are primarily used by machine tool builders to enable or disable specific machine options, bypass sensors for maintenance, or configure custom logic without rewriting the entire ladder program. Key Characteristics of Keep Relays

Internal Programmer (K17.1): Toggling this bit may allow or prevent on-machine editing of the PMC ladder. fanuc keep relay parameters exclusive

Use the cursor to highlight the specific Keep Relay address (e.g., K0005).

  1. Set PWE (Parameter Write Enable) to 1.
  2. Navigate to the PMC configuration mode—not the standard parameter menu.
  3. Access a specific "KEEPRL" screen, often requiring a higher-level password or a specific function key sequence (e.g., System → PMC → Maintain → Keep Relay).

Enable Parameter Write: Navigate to the Setting Screen and set PARAMETER WRITE to 1. Navigate to PMC Maintenance: Press the SYSTEM key. Select the PMC soft key. Choose PMCPRM (PMC Parameters) and then KEEP-RL. Title: The Guardians of Automation: The Criticality and

Interlock Control: Bypassing or enforcing safety interlocks, such as door locks or spindle start conditions.

The Hierarchy: PMC Ladder → Reads Keep Relay State → Executes Logic → Controls Machine I/O Set PWE (Parameter Write Enable) to 1

Monitor the PMC: He watched the ladder in real-time. He saw that the "Exclusive" nature was a software "handshake." Adjust the Keep Relay: By toggling a different relay, K012.4cap K 012.4