bUS

Option Communication Error

Yaskawa · Drive Fault Codes

What does bUS mean?

An error occurred during communication with an installed option card (e.g., network card, encoder card). This indicates a problem with the data exchange between the main drive unit and the option module, which can disrupt control or feedback functions.

Common Causes

  • Loose or improper physical connection of the option card to the drive's expansion slot
  • Incorrect communication settings configured in drive parameters (e.g., network address, baud rate)
  • Faulty option card hardware or an issue with the drive's internal communication interface.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Power down the drive completely and reseat the option card firmly into its slot.

  2. 2

    Verify all communication parameters (e.g., network address, baud rate, data format) are correctly configured for the specific option card.

  3. 3

    Check the cabling between the option card and any external communication network or device for integrity and proper connection.

Browse all codes in this manual (60)
Verified technical data. Last updated: March 2026

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