硬盘继电器单元 RD086-16L/B 58038776

 硬盘继电器单元 RD086-16L/B 58038776
注1–多7个集群（PM851的1个光学集群）。
注2——中央S800输入/输出。多96个单位。
集群之间的大距离为200米。
限制适用，请参阅I/O文档。
连接装置LD 800HSE
LD 800HSE
见注3
1节介绍PM891/PM86x/TP830处理器单元-冗余
3BSE036351-510 A 47
PM891/PM86x/TP830处理器单元-冗余
处理器单元冗余可用于PM861、PM864、PM865、PM866和
PM891。在这种情况下，控制器包含两个处理器单元，每个处理器单元包括
用于系统和应用软件的存储器。一个单元作为主要单元
另一种是备份（热备用）。主处理器单元控制该过程。这个
备用设备随时待命，准备在主设备出现故障时接管。这个
在不到10毫秒的时间内无冲击地完成转换。在转换过程中
过程输出被冻结。
切换后，系统作为无冗余的系统运行
只有一个处理器单元在运行。您可以更换出现故障的处理器
系统运行时的装置。进行更换后，系统
再次具有冗余处理器单元。
如果备份单元出现错误，您还可以在
系统正在运行。
备份单元中发生的错误永远不会影响主单元的操作。
主单元和备用单元在逻辑上彼此分离。
主处理器单元中的硬件错误导致系统执行正确的
转换。这些硬件错误是单个错误。
应用程序编程和通信完全不受
冗余
PM86x/TP830冗余
PM861/PM864/PM865/PM866具有一个RCU链路连接器，用于连接
RCU链路电缆（参见32页图2）。在冗余系统中，两个处理器
单元通过RCU链路电缆（大1米）连接在一起。两个处理器单元
也连接到相同的CEX总线，两个控制器中的任何一个都可以控制
膨胀装置（参见93页图29）。
S800 I/O单元通过光学模块总线和两个
每个S800 I/O集群上的TB840集群调制解调器（参见161页的图55）。这个
TP830基板上的内置电气模块总线不能用于连接
冗余系统中的S800 I/O。
底板TP830上的串行端口COM3不能用于冗余CPU
配置
PM891/PM86x/TP830处理器单元-冗余1节介绍
48 3BSE036351-510 A
PM891冗余
PM891中的冗余链路由两个物理链路组成。这些是
RCU数据链路和RCU控制链路。
RCU数据链路是用于传输数据的快速通信信道
需要保持备份CPU与主CPU同步。
数据链路采用TK855 RCU数据链路电缆。
RCU控制链路用于角色选择和CPU标识分配
（上/下）。
TK856 RCU控制链路电缆用于控制链路。
容错原则
冗余处理器单元的容错原理基于：
将备份单元持续更新到与主单元相同的状态。这
使备份单元能够在不影响周围系统的情况下进行控制
无障碍的方式。
这一原则涉及程序执行的动态划分
单元和创建处理器单元状态为的回滚点
完全定义。
在此上下文中，处理器单元的总状态定义为处理器单元的
内部状态，即处理器寄存器的内容，加上
数据存储器。
每次主单元通过回滚时，备份单元的状态都会更新
点，使备份单元能够从上次回滚恢复程序执行
如果主单元由于错误而失败，则通过点。
为了尽量减少更新中涉及的信息量，备份
只有在新回滚点之后发生更改时，才会更新单元。
在回滚点之间，这些写入数据内存的更改存储在
备份单元中的日志缓冲区。在回滚点，处理器的总寄存器
内容也被写入数据存储器，因此该信息也
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 硬盘继电器单元 RD086-16L/B 58038776


 硬盘继电器单元 RD086-16L/B 58038776

Note 1 – Maximum 7 clusters (1 optical cluster for PM851).
Note 2 – Central S800 I/O. Max. 96 units.
Max 200 m between clusters.
Restrictions apply, see I/O documentation.
Linking Device LD 800HSE
LD 800HSE
see Note 3
Section 1 Introduction PM891/PM86x/TP830 Processor Unit – Redundancy
3BSE036351-510 A 47
PM891/PM86x/TP830 Processor Unit – Redundancy
Processor unit redundancy is available for PM861, PM864, PM865, PM866, and
PM891. In this case, the controller contains two processor units, each including
memory for system and application software. One unit is acting as primary, the
other is backup (hot stand-by). The primary processor unit controls the process. The
backup stands by, ready to take over in case of a fault in the primary. The
changeover is done bumplessly and in less than 10 ms. During the changeover, the
process outputs are frozen.
Following a changeover, the system operates as a system without redundancy with
only one processor unit in operation. You can replace the malfunctioning processor
unit while the system is running. After the replacement is carried out, the system
once again has a redundant processor unit.
If an error arises in the backup unit, you can also replace the backup unit while the
system is running.
Errors which occur in the backup unit can never affect the primary unit's operation.
The primary unit and the backup unit are logically separated from one another.
Hardware errors in the primary processor unit cause the system to perform a correct
changeover. These hardware errors are single errors.
The application programming and the communication are totally unaffected by the
redundancy.
PM86x/TP830 Redundancy
The PM861/PM864/PM865/PM866 has an RCU Link Connector for connecting the
RCU Link Cable (see Figure 2 on page 32). In a redundant system the two processor
units are linked together with the RCU Link Cable (max 1 m). Both processor units
are also connected to the same CEX-Bus and either of the two can control the
expansion units (see Figure 29 on page 93).
S800 I/O units are connected to the two CPUs via the optical ModuleBus and two
TB840 cluster modems on each S800 I/O cluster (see Figure 55 on page 161). The
built-in electrical ModuleBus on the TP830 baseplate cannot be used for connecting
S800 I/O in a redundant system.
The serial port, COM3 on the baseplate TP830, cannot be used in redundant CPU
configuration.
PM891/PM86x/TP830 Processor Unit – Redundancy Section 1 Introduction
48 3BSE036351-510 A
PM891 Redundancy
The Redundancy Link in PM891 consists of two physical links. These are the
RCU Data Link and the RCU Control Link.
The RCU Data Link is a fast communication channel used to transfer the data
required to keep the backup CPU synchronized with the primary CPU.
TK855 RCU Data Link Cable is used for the data link.
The RCU Control Link is used for role selection and CPU identity assignment
(UPPER/LOWER).
TK856 RCU Control Link Cable is used for the control link.
Fault Tolerance Principle
The principle of fault tolerance in the redundant processor units is based on
continuous updating of the backup unit to the same status as the primary unit. This
enables the backup unit to assume control without affecting surrounding systems in
a bumpless manner.
This principle involves dynamic division of the program execution into execution
units and the creation of rollback points at which the processor unit's status is
completely defined.
In this context, the processor unit's total status is defined as the processor unit's
internal status, that is, the contents of the processor registers, plus the contents of the
data memory.
The backup unit's status is updated each time the primary unit passes a rollback
point, enabling the backup unit to resume program execution from the last rollback
point passed, should the primary unit fail due to error.
In order to minimize the amount of information involved in the update, the backup
unit is updated only with the changes taking place since the latest rollback point.
Between rollback points, these changes that writes in the data memory, are stored in
a log buffer in the backup unit. At a rollback point, the processor's total register
contents are also written into the data memory, so that this information is also
logged. Once the rollb
 硬盘继电器单元 RD086-16L/B 58038776