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At present, production process control in power plant, usually under the volume of the controlled object, location and working environment, use DCS or PLC control system, and remote IO and SCADA system. The traditional DCS system IO card mostly adopts the parallel slot type structure, can not be distributed installation, not suitable for boiler wall temperature measuring points distributed application environment; remote IO and SCADA system rarely involved in important control, product stability and reliability, as well as the poor real-time data, it is difficult to adapt to the large-scale power plant control demand.DCS is the distributed computer system that contain process control level and process monitoring with communication network to link, It is toward a more open, standardization, more abundant information automation direction, Now the domestic and international mainstream control system manufacturers in the continuous improvement of the system structure, to a distributed, modular and field bus is developing in three directions.Based on this, this paper analyzes the industrial automation trend of the current decentralized control system and modern process, put forward a kind of a new generation of more safe and reliable based on field bus technology for distributed modular distributed control system, the system ’s core content is based on the CAN bus technology, design and development of a series of new type of field bus intelligent module, instead of the traditional DCS input/output boards and remote IO products.This paper organized a DCS network structure, proposed the concept of distributed intelligent measure and control module, and aimed at the mainstream fieldbus and micro controller undertook in-depth survey, design and planning of distributed intelligent monitoring module, the system architecture design, and to identify the specific development program. In this paper, design and development 6 kind of signal type intelligent measure and control module, including the standard analog signal input module, a thermocouple signal input module, thermal resistance signal input module, standard analog signal output module, switch signal input module and the switch signal output module.Then the paper introduces intelligent measure and control module application in power plant control system, the intelligent measurement and control module performance test, and from several aspects introduced in system reliability work.In this paper, through thorough investigation and the application of long experience, absorbed the tradition DCS stability design and remote 10 distributed advantages, The CAN bus intelligent measure and control module based on simple structure but reliable communication, abandon the common backplane slots, using a new modular structure of metal packaging, single terminal, power supply communication dual redundant module improved structure for the module, operation stability and signal acquisition accuracy improves a lot, including the use of two level watchdog monitors the operation of the microprocessor and the power supply, a signal input filtering, anti-shake software, thermocouple cold end compensation module, thermocouple, thermal resistance module linearization, realized the highest precision and stability.Numerous project application, distributed intelligent measure and control module based on the CAN bus designed by this paper stable operation, data is reliable, has high precision, and can be widely applied in the different needs of the decentralized control field.
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