EFB fault 2
ABB · ACS580
What does 6685 mean?
This is a generic fault reserved for the embedded fieldbus (EFB) protocol application, indicating an unspecified error within the EFB communication stack or protocol execution. The precise cause and resolution are dependent on the specific fieldbus protocol implemented.
Common Causes
- Transient communication error on the fieldbus network (e.g., brief signal interference or network voltage dip).
- EFB internal software exception or buffer overflow within the communication stack.
- Undocumented protocol-specific error condition triggered by an unusual sequence of commands from the fieldbus master.
- Fieldbus master sending malformed or unsupported telegrams to the drive's EFB module.
- EFB module internal diagnostic failure not covered by more specific fault codes.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Reset the EFB module by cycling power to the drive, then monitor for recurrence.
- 2
Monitor fieldbus network activity using a protocol analyzer (e.g., Wireshark) for error frames or unexpected traffic bursts.
- 3
Review event logs in the fieldbus master for any related communication errors or warnings indicating an issue on the master side.
- 4
Update EFB module firmware and main drive firmware to the latest compatible versions available.
- 5
Temporarily disconnect other devices from the fieldbus segment to isolate potential network interference sources.