Chapter 4. Error Analysis and Fault Isolation
EK–SMCPP–UG. A01
4–19
4.7
I/O Module Error Reporting
The EMU monitors the status of all the I/O modules for the following error
conditions:
•
The installation of incompatible I/O modules
•
A TERMPOWER problem
4.7.1 Incompatible I/O Modules
Only when all I/O modules are the same type can an UltraSCSI RAID subsystem
function properly. The DIGITAL UltraSCSI controller only supports single-
ended, UltraSCSI buses. Therefore, you can only use single-ended I/O modules.
Installing any other module type creates an error condition that the EMU reports
to the controller.
4.7.2 No I/O Module Installed
Failure to install, or installing an I/O module incorrectly, automatically disables
the SCSI bus within the enclosure. Without an I/O module, there is no
TERMPOWER available to the internal SCSI bus and the bus cannot function.
4.7.3 TERMPOWER Errors
The I/O module displays the TERMPOWER status for both the internal and the
external bus (see Figure 4–6). The nominal TERMPOWER voltage for both
buses is +5 V dc.
