6684

EFB load fault

ABB · ACS880

What does 6684 mean?

The embedded fieldbus (EFB) protocol firmware could not be loaded, or there's a version mismatch between the EFB protocol firmware and the drive firmware. This means the EFB functionality is completely disabled. The drive cannot communicate via EFB.

Common Causes

  • Corrupted Embedded Fieldbus (EFB) protocol firmware file in the drive's memory, preventing proper loading.
  • EFB firmware version incompatibility with the current drive's main firmware, typically after an update of the main drive software.
  • Transient power interruption or internal memory write error during the EFB firmware loading process.
  • Faulty EFB option module hardware preventing correct firmware storage or execution on the module itself.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify EFB option module firmware version compatibility against the drive's main firmware version using the control panel (e.g., menu `INFO > VERSIONS`).

  2. 2

    Attempt to re-upload the EFB protocol firmware file to the drive via a communication port (e.g., USB or Ethernet) using the manufacturer's software tool.

  3. 3

    Perform a full power cycle of the drive system (main power disconnect for at least 30 seconds) to clear temporary memory states.

  4. 4

    Physically remove the EFB option module, inspect its connector pins for damage, and firmly reinsert it into its slot.

  5. 5

    As a last resort, temporarily replace the EFB option module with a known-good module to confirm hardware integrity.

Browse all codes in this manual (116)
Verified technical data. Last updated: March 2026

Related Faults