SMAR MB-700, Руководство пользователя

Страница: 89 / 116

Redundancy Hot Standby
7.5
setting Sync_Main. After that, through the synchronism path the other one automatically will be set
as Backup . This designates physically who should be, in other words, the Preferential and the
Redundant processor module respectively. This way, Main and Backup can be understood simply
as labels.
•
RED_ROLE_L / RED_ROLE_R
It reflects the configuration made at FUNCTION_IDS, identifying the
Role of the module, Sync_Main
or Sync_Backup .
•
RED_STATE_L / RED_STATE_R
Active - runs all the tasks and generates all the data.
Standby – does not run the tasks, but just receives all the data generated by the other one and
stands ready to assume, if necessary.
Not Ready – redundancy not available.
The different failures that may occur in such system, lead it to a
switch over , when the Standby
bumplessly becomes Active and vice-versa. The possible reasons for a switch over , divided in two
types, are as follows:
General Failures
When the whole processor module fails, this comprises:
- Hardware
Failure.
- Power Off.
- Removal of the processor module from the Backplane.
Bad Condition Failures
When one of the processor module interfaces fails:
-
Modbus communication failure (hardware or cable; in the case of operating as master).
The system is capable of checking which one has the best conditions, electing it as the
Active .
It is certain the recovery of one failure at a time. That is, once a fail has occurred, a second fail will
be recovered by redundancy just if the first fail has been fixed. While the failure is not fixed, the
system has the redundancy not fully available (in case of
Bad Condition Failures ) or even not
available (in case of General Failures ).
For the case of
General Failures , as soon as the failed module recovers a healthy state or is
replaced, the modules automatically become a redundant pair again. That is, the system
automatically recognizes a new inserted module.
•
RED_SYNC_STATUS_L / RED_SYNC_STATUS_R
This parameter reflects all the possible status of the synchronism between the modules.
SYNC STATUS DESCRIPTION
Stand Alone
There is just one module operating. If the system has been synchronized at
least once, and this value appears, it indicates that the other module had a
General Failure.
Synchronizing
The modules are checking their configuration with each other in order to
reach the
Synchronized status. It can take up to 9 min. at maximum when
the system waits for the module in “Not Ready” state get its live lists
completed.
Updating Remote
Just after the download of the configuration, the module transfers the whole
configuration to the other one through the synchronism path.
Maintenance
The module is being configured by the other module through the
synchronism path or by the SYSCON. If it appears for both “
L ” and “ R ”
parameters it indicates that none of the modules have been configured.