FOXBORO FBM243 P0914TK通信模块
链中的最后一个PQM和主计算机需要端接电阻器和端接电容器，以确保负载的正确电气匹配并防止通信错误。在所有PQM上使用端接电阻器会降低通信网络的负载，而在末端省略它们可能会导致反射，从而导致通信错误。外部安装120Ω¼瓦终端电阻器和1 nF电容器。尽管这些值的任何标准电阻器和电容器都是合适的，但这些组件也可以作为组合终端网络从GE Multilin订购。每个通信链路必须只有一台计算机（PLC或DCS）发出命令，称为主机。主设备应位于中央，可用于查看每个PQM（称为从设备）的实际值和设定值。使用Modbus RTU协议的其他GE Multilin继电器或设备可以连接到通信链路。
The last PQM in the chain and the master computer require a terminating resistor and terminating capacitor to ensure proper electrical matching of the loads and prevent communication errors. Using terminating resistors on all the PQMs would load down the communication network while omitting them at the ends could cause reflections resulting in communication errors. Install the 120 Ω, ¼ watt terminating resistor and 1 nF capacitor externally. Although any standard resistor and capacitor of these values are suitable, these components can also be ordered from GE Multilin as a combined terminating network. Each communication link must have only one computer (PLC or DCS) issuing commands called the master. The master should be centrally located and can be used to view actual values and setpoints from each PQM called the slave device. Other GE Multilin relays or devices using the Modbus RTU protocol can be connected to the communication link.
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