基于ARM的分布處理單元的結構框，這和一般的分布處理單元的結構非常相似。這里主要把處理單元分為6部分：ARM控制器、上層網絡模塊、電源管理模塊、存儲器模塊、低層網絡模塊和時鐘模塊。ARM控制器和存儲模塊組成了基本的嵌入式系統(tǒng)，整個DCS控制系統(tǒng)的數據處理和控制策略都是在這里處理的。上層網絡模塊主要是指和管理層通信的主/冗余網絡和一個實現主/冗余分布處理單元進行數據交換的網絡，這部分的主要功能是完成管理層對DCS控制系統(tǒng)的實時檢測和實現主/冗余分布處理單元的數據冗余。底層的網絡模塊是由分為主次的2條485網絡組成，此模塊主要實現ARM控制器的I/O卡件之間的數據通信。存儲器模塊可分為兩部分，一部分用來管理存放操作系統(tǒng)，另一部分用來管理存放實時數據。電源模塊和時鐘模塊分別實現電源的管理和時鐘的管理。

The structure block diagram of arm based distributed processing unit is shown in Figure 2, which is very similar to the structure of general distributed processing unit. Here, the processing unit is mainly divided into six parts: arm controller, upper network module, power management module, memory module, lower network module and clock module. Arm controller and memory module constitute the most basic embedded system. The data processing and control strategy of the whole DCS control system are processed here. The upper network module mainly refers to the main / redundant network communicating with the management and a network realizing the data exchange of the main / redundant distributed processing unit. The main function of this part is to complete the real-time detection of the DCS control system by the management and realize the data redundancy of the main / redundant distributed processing unit. The bottom network module is composed of two 485 networks divided into primary and secondary. This module mainly realizes the data communication between the i/o cards of the arm controller. The memory module can be divided into two parts, one is used to manage and store the operating system, and the other is used to manage and store real-time data. The power module and the clock module realize the management of power supply and clock respectively.