Redundancy Defined
A redundant link uses two LC modules to communicate with the field devices. One
of the modules is designated the primary module; the other is the secondary module.
In operation, the primary LC module communicates with the field devices and
moves the data to/from the Ovation Controller. If communication between the
primary module and the field devices fail, the secondary module takes over
communication.
5-3. SLC Algorithm Support for Redundancy
The SLC algorithms include support for redundant links. Refer to “Ovation
Algorithms Reference Manual” (R3-1100) for details.
The algorithms which provide data I/O for the Ovation LC module have the ability
to transfer the data between the Controller and either of a redundant pair of LC
modules. These algorithms include the following:
• SLCAIN
• SLCAOUT
• SLCDIN
• SLCDOUT
5-4. Redundant Hardware Configuration
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Westinghouse Proprietary Class 2C
The hardware addresses of both LC modules are provided to the algorithm as
parameters. The digital inputs, PSTA and SSTA, are used to select the primary or
secondary module for the data transfer.
The SLCSTAT algorithm is used in the redundancy scheme to determine if the
selected module is still communicating with the field devices. The LC module’s
hardware watchdog timer state indicates the success or failure of the
communication.


冗余定义
冗余链路使用两个LC模块与现场设备通信。一
其中一个模块被指定为主模块；另一个是辅助模块。
在运行中，主LC模块与现场设备和
在Ovation控制器之间移动数据。如果
主模块和现场设备出现故障，由辅助模块接管
表达
5-3. SLC算法对冗余的支持
SLC算法包括对冗余链路的支持。参见“鼓掌”
算法参考手册”（R3-1100）了解详细信息。
为Ovation LC模块提供数据I/O的算法具有
在控制器和冗余LC对之间传输数据
模块。这些算法包括：
•斯尔坎
•SLCAOUT
•SLCDIN
•SLCDOUT
5-4. 冗余硬件配置
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两个LC模块的硬件地址都提供给算法，如下所示：
参数。数字输入PSTA和SSTA用于选择主或
用于数据传输的辅助模块。
SLCSTAT算法用于冗余方案，以确定
所选模块仍在与现场设备通信。LC模块的
硬件看门狗定时器状态指示硬件的成功或失败
表达