BENTLY 3500/15 127610-01超速保护
只有主从设备才能在PROFIBUS上传输过程数据和诊断信息。因此，主从机的状态还包含备份从机的信息。有关详细信息，请参阅从属文档。尽管备份从机没有与主机的活动数据传输，但CI854/CI854A能够监控备份从机。备份从属设备在Livelist中可用，如果配置了冗余，则将激活监控。如果备份从属设备发生故障，则将在主从属设备的ExtendedStatus（扩展状态）中设置信息“冗余从属设备不存在”。为了在发生错误时允许从设备进行故障切换，CI854/CI854A具有特殊的监控功能。如果冗余从属设备受到干扰，CI854/CI854A将等待（2*看门狗时间+1），然后指示从属设备的连接断开。在此期间，从设备可以执行切换并继续正常数据交换，而不中断通信。
Only the primary slave can transfer process data and diagnostic information on the
PROFIBUS. Therefore the status of the primary slave also contains the information
of the backup slave. Please refer to the slave documentation for the details.
Although the backup slave has no active data transmission with the master the
CI854/CI854A is able to monitor the backup slave. The backup slave is available in
the Livelist and if redundancy is configured the monitoring will be activated. If the
backup slave fails, the information "Redundant slave does not exist" will be set in
the ExtendedStatus of the primary slave.
To allow the slave a failover in case of an error the CI854/CI854A has a special
monitoring function. If the redundant slave gets disturbed the CI854/CI854A waits
for (2* watchdog time + 1) before connection down will be indicated for the slave.
During this time the slave can perform a switchover and proceed with the normal
data exchange without interrupting the communication.
