YPK112A 3ASD573001A13 ABB 通道断电器模块

YPK112A 3ASD573001A13 ABB 通道断电器模块

PLC自带的通讯口和扩展通信板、通讯单元所提供的通讯口，功能是一致的，是对CPU通讯功能的扩展。很多时候，CPU需要跟不止一个终端设备通讯，并且执行不同的通信协议（通用的MODBUS-RTU/RS485，以太网，还有不同 PLC厂家各自专有的协议如AB的DH485，甚至Hart协议和布朗协议等现场总线）：

1、与HMI上位计算机通讯，上位机系统需要跟现场的PLC交换数据。

2、人机界面（操作者接口），需要完成用户与PLC之间的交互，显示工艺流程中的各种数据并生成各类图表，将操作人员命令写入PLC内存，也需要占用通信端口。

3、与编程人员的编程设备通讯（编程器等），在线完成软件编辑，查看PLC运行状态。

4、高端的PLC还支持现场总线协议，可以与现场仪表通信，如Hart和Brain协议，实现和支持以上协议的现场仪表通信（而不是采用数字量和模拟量）。

以上几项工作往往需要同时完成，这样CPU自带的通讯口数量就不够了，需要扩展，就会用到通讯板或通讯单元

YPK112A 3ASD573001A13 ABB 通道断电器模块

The communication port of PLC and the communication port provided by the expansion communication board and communication unit have the same function, which is an extension of the communication function of the CPU. Many times, the CPU needs to communicate with more than one terminal device and execute different communication protocols (common MODBUS-RTU/RS485, Ethernet, and different PLC manufacturers' respective proprietary protocols such as AB's DH485, and even Hart and Brown protocols and other fieldbuses) :

1. Communication with HMI upper computer, the upper computer system needs to exchange data with the PLC on site.

2, human-machine interface (operator interface), need to complete the interaction between the user and the PLC, display various data in the process and generate all kinds of charts, the operator command into the PLC memory, also need to occupy the communication port.

3, communicate with the programming equipment of the programmer (programmer, etc.), complete the software editing online, and check the operating status of the PLC.

4, high-end PLC also supports fieldbus protocol, can communicate with the field instrument, such as Hart and Brain protocol, to achieve and support the above protocol field instrument communication (rather than using digital and analog).

The above several tasks often need to be completed at the same time, so that the number of communication ports with the CPU is not enough, and it needs to be expanded, which will use the communication board or communication unit