Basic I/O Unit Error - Slot Number

What does A408.00 to A408.07 mean?

When an error occurs in a Basic I/O Unit, this word stores the slot number (00 to 09 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 in the indicated slot
• Improper seating or connection of the I/O Unit in its slot
• Internal fault within the Basic I/O Unit itself

Click steps to track your progress.

1. 1

   Identify the problematic Basic I/O Unit by checking the slot number indicated in A408.00 to A408.07

2. 2

   Visually inspect the identified I/O Unit for any physical damage or loose connections

3. 3

   Re-seat the Basic I/O Unit firmly into its slot

4. 4

   Replace the Basic I/O Unit if visual inspection or re-seating does not clear the error