I xx .Fault

Modbus Master Channel Data Fault

Allen-Bradley · Compact 5000 I/O Serial Module

What does I xx .Fault mean?

This boolean tag indicates that the channel data for the Modbus master is inaccurate and cannot be trusted for use in the application. When set to 1 (Bad), it signifies an active fault condition within the module or its communication. The tag automatically resets to 0 (Good) once the underlying condition causing the inaccuracy is resolved.

Common Causes

  • Module data inaccuracy due to internal processing error
  • Underlying communication issue affecting data integrity on the Modbus master channel
  • Misconfiguration of Modbus master parameters leading to corrupted data

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Troubleshoot the module to identify the specific cause of data inaccuracy affecting the Modbus master channel.

  2. 2

    Inspect all physical serial communication cable connections at the module and Modbus slave device terminals for proper seating.

  3. 3

    Cycle power to the module to attempt clearing any transient internal faults.

Browse all codes in this manual (28)
Verified technical data. Last updated: March 2026

Related Faults

Source: Allen-Bradley Compact 5000 I/O Serial Module