Special I/O Unit Number Duplication Error

What does A401.13 mean?

This fault occurs when a Special I/O Unit's unit number is duplicated, or when a Special I/O Unit's allocated memory words conflict with a Basic I/O Unit on an Expansion Rack due to an incorrect starting word setting. When this error occurs, the CPU Unit operation will stop, and the ERR/ALM indicator on the front of the CPU Unit will light. The Duplication Error Flag (A401.13) and the corresponding specific unit flag (A411.00 to A416.15) will be set to ON.

• Two or more Special I/O Units are configured with the same unit number (00-95).
• A Special I/O Unit's allocated memory words conflict with a Basic I/O Unit on an Expansion Rack due to incorrect Expansion Rack starting word settings.

Click steps to track your progress.

1. 1

   Identify the conflicting unit numbers by checking the status of bits A411.00 to A416.15.

2. 2

   Verify and correct the unit number settings for all Special I/O Units to ensure each is unique (00-95).

3. 3

   Review the Expansion Rack's starting word settings to prevent overlap with Special I/O Unit word allocations.

4. 4

   Clear the error flag (A401.13) after correcting the duplication.