IS200TDBTH6A系统模块卡件
每个PLC的设计都是模块化的，包括一个带有电源模块的机架、一个CPU模块和执行应用程序所需特定操作的其他模块。与其他三重系统不同，GMR不需要持续的处理器同步，大大降低了软件和硬件共模故障的概率。下图显示了示例GMR系统的基本部分——三个PLC、三条Genius总线、每个PLC中的三个Genius总线控制器、一个Genius块输入组和一个Genus块输出组。在实际系统中，可以有许多输入组、输出组和三重总线。尽管图示显示了仅连接到一个现场设备的每个块，但每个块或块组最多可以连接32个现场设备（如果使用自动测试，则为31个）。Genius总线控制器和总线一到三条Genius总线为GMR系统传输和通信数据。冗余总线控制器和总线电缆可防止通信子系统中的单点故障。总线控制器通过维护两个独立的板载RAM存储器来管理其总线和CPU之间的数据传输。一个与总线接口，另一个与CPU接口。总线控制器自动在这两个存储器之间传输数据，使数据在需要时可用于总线或CPU。除了用于数据之外，Genius总线还提供PLC之间的通信，PLC定期交换状态数据。还可以交换有限数量的应用程序数据。单独的总线可用于PLC之间以及与使用Genius协议通信的主机设备之间的额外数据交换。Genius总线协议提供对传输错误的固有保护。每个发送设备发送每个比特三次。每个接收设备对接收到的每个比特执行三取二表决，并对每个分组执行CRC校验和。该过程自动纠正错误接收到的任何比特，并消除重传的需要。LOAD LOAD Input Device Geni 46629 PLC、总线控制器和总线同步与其他三重系统不同，GMR不需要持续的处理器同步，大大降低了软件和硬件共模故障的概率。在GMR系统中，每个PLC通常运行相同的应用程序。在系统启动期间，应用程序数据可选地在PLC之间同步。当一个或多个PLC离线后重新启动时，也可以选择同步。初始系统程序同步应用程序初始化后，每个PLC运行启动诊断，检查所有系统组件的状态，并提供有序、受控的启动。如果发生任何错误，则将其记录到PLC中的故障表中，并通过诊断状态位提供给应用程序。初始化错误可能会或可能不会停止PLC；这由为应用程序设置的GMR配置确定。部分重新启动系统程序初始化如果系统继续运行时一个或多个CPU脱机，则在重新引入脱机CPU时自动启动“热启动”。
Each PLC is modular in design, consisting of a rack with a power supply module, a CPU module, and other modules that perform specific operations needed for the application. Unlike other triplicated systems, GMR does not require ongoing processor synchronization, greatly reducing the probability of software and hardware common-mode failures. The illustration below represents the basic parts of a sample GMR system--three PLCs, three Genius busses, three Genius Bus Controllers in each PLC, one input group of Genius blocks, and one output group of Genius blocks. In an actual system, there can be many input groups, output groups, and triplex busses. Although the illustration shows each block connected to just one field device, there can be up to 32 field devices connected to each block or block group (31 if autotesting is used). Genius Bus Controllers and Busses One to three Genius busses transmit and communications data for the GMR system. Redundant Bus Controllers and bus cables prevents a single point of failure in the communications subsystem. A Bus Controller manages data transfer between its bus and the CPU by maintaining two separate on-board RAM memories. One interfaces with the bus and the other interfaces with the CPU. The Bus Controller automatically transfers data between these two memories, making data available to the bus or to the CPU when it is needed. In addition to being used for data, the Genius busses provide communications between the PLCs, which regularly exchange status data. A limited amount of application data can also be exchanged. Separate busses can be used for additional data exchanges between the PLCs and with host devices that communicate using Genius protocol. The Genius Bus Protocol provides inherent protection against transmission errors. Each transmitting device sends each bit three times. Each receiving device performs a 2-out of 3 vote on each bit received, and a CRC checksum on each packet This process automatically corrects any bits received in error and eliminates the need for retransmission. LOAD LOAD Input Device Geni Geni 46629 PLCs, Bus Controllers and Busses Synchronization Unlike other triplicated systems, GMR does not require ongoing processor synchronization, greatly reducing the probability of software and hardware common mode failures. In a GMR system, each PLC typically runs the same application program. Application program data is optionally synchronized among the PLCs during system startup. It is also optionally synchronized whenever one or more PLCs is taken offline and then restarted. Initial System Program Synchronization Upon initialization of the application program, each PLC runs a startup diagnostic, checks the status of all system components and provides an orderly, controlled startup. If any errors occur, they are logged into a fault table in the PLC and made available to the application program through diagnostic status bits. Initialization errors may or may not stop the PLC; this is determined by the GMR configuration set up for the application. Partial Restart System Program Initialization If one or more CPUs are taken offline while the system continues to operate, a “warm start” is automatically initiated when the offline CPU(s) are re-introduced.
