4.3.3 Application of Thresholds
Application of thresholds by the EHS is rate based. An FRU exceeds its threshold
when it accumulates a certain number of a given error type in a specified time
period. Table 4–13 lists the thresholds associated with each FRU and error type.
In most cases, more than one type of error can result in the isolation of an FRU.
For each FRU and error type, a separate threshold is applied. The threshold
for an error type of a specific FRU must be exceeded before the module is
deconfigured.
For example, both NXIO and I/O errors may isolate an ATM module. EHS
maintains separate thresholds for NXIO and I/O errors for each ATM module.
When one of the errors occurs and is isolated to an ATM, the threshold for that
error type on that ATM is applied. If the threshold is exceeded, the ATM is
deconfigured.
Table 4–13 FRU Thresholds
Error
Type
Error
Limit
Time
Period
1
Comments
CPU Module
CPU/MEM
faults
3
12
A CPU/MEM fault results in the temporary removal
of the CPU module from service. The CPU will be
reconfigured into the system if this threshold is not
exceeded.
Resynch
abort errors
3
1
Resynch abort errors result in the termination of the
Resynch operation. When the threshold for this error
is exceeded, the CPU module is marked as broken.
System downtime must be scheduled to repair the
problem since the only CPU module has failed.
Memory SIMMs
Single-bit
memory
errors
3
12
Each single-bit memory error is attributed to a row
of memory SIMMs on a single MMB. Each SIMM row
has an individual threshold. When the threshold for
the SIMM row is exceeded, the CPU module on which
the SIMM resides will be removed from service if the
system operating mode is Duplex.
I/O ATM Module
Clock phase
errors
3
12
Each clock phase error results in the temporary
removal from service of a zone. When the zone returns
to service, it will be resynchronized automatically if the
threshold is not exceeded.
Transient
I/O errors
3
12
When this threshold is exceeded, the zone in which
the ATM resides is removed from service, except in a
Simplex system.
I/O Expansion Module
1
In hours
(continued on next page)
Error Handling and Analysis 4–17