Basic I/O Unit Error - Rack Number

What does A408.08 to A408.15 mean?

When an error occurs in a Basic I/O Unit, this word stores the Rack number (00 to 03 hexadecimal) where the error was detected. The CPU Unit continues operating, but the ERR/ALM indicator on the front of the CPU Unit will flash. The presence of this error is also indicated by A402.12 being ON.

• Hardware malfunction within a Basic I/O Unit located on the indicated rack
• Faulty backplane or power supply on the identified rack
• Issues with the expansion cable connecting to the problematic rack

Click steps to track your progress.

1. 1

   Identify the problematic Rack by checking the rack number indicated in A408.08 to A408.15

2. 2

   Inspect all Basic I/O Units on the identified rack for proper seating and connection

3. 3

   Check the integrity of the expansion cables connecting to the identified rack

4. 4

   Verify the power supply to the identified rack is stable and within specifications

5. 5

   Consider swapping Basic I/O Units between slots on the identified rack to isolate the faulty component