Issue 5 - September 2006
Page 35 of 65
run through its off-line diagnostics to re-check its health, which is indicated by the front lights
sequencing and the green health light being turned on.
When this has completed, the front LED’s are extinguished for approximately 3 seconds and
then are illuminated, the processor is now ready to be warm started into the system.
The warm start command instructs the two operating processors to allow the warm starting
processor to read their memory. The warm starting processor first reads the system data and
programme code which is static and finally, when this is completed, its requests the two
operating processors to halt for approximately 0.5 seconds whilst it reads the varying data. This
being completed all three processors resume full operation.
In the event that an error is found in the warm starting processor during this sequence and it
fails to warm start, the two operating processors continue on without the third processor.
On the successful culmination of the system repair the error clear should now be operated to
clear the error history to enable new faults to be readily interpreted.
6.2.3.3 Bus
Buffer
Module
The spare bus buffer module should be visually checked against the user documentation. The
faulty bus buffer module can now be removed and replaced by the spare module. The error
history clear should now be operated to allow any new faults that occur to be readily diagnosed.
6.2.3.4 Power Supply Module
The spare power supply module should be visually checked.
The faulty power supply should first be switched off using the front panel switch before
unscrewing the chassis fixing screws and then removed.
The spare module should then be plugged in and powered up. The error history clear should
now be operated to allow any new faults that occur to be readily diagnosed.
6.2.3.5 History
Clear
During a maintenance repair activity the history error report should first be printed before the
fault bits are cleared by use of the error clear facilities within TriBuild. This action is important as
by clearing the errors all historical errors are lost and any new errors that occur will be readily
diagnosed. Also clearing the error bits will ensure that if a time constraint timer is configured in
the application, this will be reset, after one complete LFD test cycle, until the next error appears.
6.2.4 Sequence
of
Repair
Certain faults, for example Power Supply, Main Processor and Bus Interface Module, will give
rise to both alarms associated with the fault as well as additional alarms. For example when
one of the dual power supply modules in a chassis fails additional to the power supply failure
alarm, each I/O module within the chassis will be reporting that one of its power supplies has
failed and indicate a health problem. It is therefore important to repair the SC300E in a logical
order or sequence.
The following order should be followed assuming fault indication for each item is given: -
Priority
1
Chassis Power Supply Units
2
Main
Processor
Units
MPP
3
Bus
Interface
Units
MBB
4
I/O
Modules
5
Field
Connection
After each repair the history should be cleared and the next item to appear dealt with.
