ABB SNAT604 5761861-2B卡件模块
从站冗余CI854/CI854A支持PROFIBUS用户组织（PNO）指定的PROFIBUS从站冗余。冗余从站有两个PROFIBUS接口，一个用于主站，一个备用从站。如果使用线路冗余，则其中一个接口连接到线路A，另一个连接到线路B。如果不使用，则两个接口都连接到相同的PROFIBUS电缆。备份从设备的PROFIBUS地址始终是主从设备的地址加上64。Control Builder中的配置可确保当从属设备设置为冗余时，两个地址都可用。如果从设备发生冗余切换，PROFIBUS地址也会切换。这意味着，无论谁是主服务器，谁是备份服务器，主服务器始终具有分配的地址，备份服务器始终具有地址+64。这种冗余被称为“飞行冗余”。
Slave Redundancy
The CI854/CI854A supports the PROFIBUS slave redundancy like specified by the
PROFIBUS User Organization (PNO).A redundant slave has two PROFIBUS interfaces, one for the primary and one for
the backup slave. If line redundancy is used, one of the interfaces is connected to
line A and the other to line B. If not, both interfaces are connected to the same
PROFIBUS cable. The PROFIBUS address of the backup slave is always the address of the primary slave plus 64. The configuration in the Control Builder
ensures, that both addresses are available when the slave is set redundant. If a
redundancy switchover of a slave occurs, also the PROFIBUS addresses are
switched. That means, the primary slave always has the assigned address and the
backup slave always has the address + 64 regardless of who is the primary and who
is the backup. This kind of redundancy is called "flying redundancy".
