The Design And Implementation Of DCS Control Station’s Main Control System Based On ARM And μC/OS-Ⅱ

After nearly forty years of development, DCS (Distributed Control System) has improved its function and performance steadily, improved the level of automation of industrial production, provided important reference data for production management, and established its irreplaceable position in large and complex industrial processes. By the study of the main control system of DCS control station, the paper designs and implements the main control system based on ARM micro controller and embedded real-time OS μC/OS-Ⅱ, with the specific function requirements.In the process of system design, control and communication are always the key function, and real-time and reliability are always the basic requirements. The main control system consists of two control cards. The two cards have the same hardware and software configurations, working in master-slaver hot standby mode. They communicate with host PCs with Ethernet, communicate with meters with CAN. They also need to execute the function of explanation, executation and storage of control algorithms.In order to improve the reliability, the communication network also adds some redundant processes, in addition to control cards’ hot standby. The Ethernet network consists of two paralled and independent Ethernet lines. And the CAN network is a round network with two CAN transreceiver.The main control cards are based on micro controller STM32F407ZG with core of ARM Cortex-M4and embedded real-time OS μC/OS-Ⅱ. This paper gives the details of the design of circuit, the transplant of the OS, and the development of application program.As for circuit design, this paper designs circuits of power-on competition and state monitoring via RS trigger and D trigger, circuits of first Ethernet via built-in MAC and external physical layer interface chip DP83848I, circuits of the second Ethernet via W5100, circuits of CAN network via two built-in CAN modules and two external transreceivers TJA1051T/3, circuits of expanding RAM via CY62177EV30for the storage of control algorithms, circuits of interface between micro controller and calendar clock chip PCF2129A, and circuits of basic HM interface with leds and dial switch.As for software design, it need to meet the requirements of capacity of7kinds of meters(DI, DO, AI, AO, RTD, TC, PI),1024digital I/O points,512analogic inputs,256analogic outputs,255loops, and the requirements of speed of executing control algorithms one time per second. The work of software design includes transplant of μC/OS-Ⅱ, program of dual Ethernet communication, program of dual CAN communication, program of explanation, excitation, storage and recovery of control algorithms, program of faults reports of control cards, meters and network, and program of necessary status indication.