Multi-Parameter Sensor Networks Based On Fieldbus And Embedded Systems

Human could not live without environment. The question, how to detect unknown world or research known world quickly, and use geography, climate and resources rationally, became one of the most important issues to be solved when we want to make a coordinated development against the environment. Sensors, which are always being researched widespread and in-depth, connect human and the world. Except for detecting environment factors, sensors also take the responsibility to recognize objects, obtain signals, and assist industrial control applications. The sensor technology is one of the frontier technologies.As the rise of the Internet, science and technology development rushes into a new era of mass information acquisitions and data communications. Social development needs macro analysis, global control and information exchange, which depend on the technology of network. The trend of network is also present in sensor network, while more and more sensors are designed with standardized interfaces and protocol functions. Meanwhile, the Internet of thing must include sensor network, the most of information transmissions would occur between sensors.The concept of fieldbus occurred in 1984, which was defined as one of the digital communication technologies that applied in industrial applications. Fieldbus is known as excellent communication between equipments or between equipments and control devices, highlighted ability to bidirectional, serial, nodal transmission. It could be regard as an open network protocol. Up to now, there are several kinds of standardized protocols of fieldbus, with the same features of good operability and poor interoperability. The fieldbus are still applied to many applications that needed network connections, while its wired connection way will not be eliminated.However, the sensor networks will be more and more designed as wireless sensor networks. One independent sensor node is also one network node, which can monitor environment, collect data, and also has the radio receiver and transceiver and establishes network. Through the network, data is transmitted and summarized, and in a server or user terminal the data is used to display and global control. Wireless sensor networks will be everywhere in the foreseeable future.This paper's topic originated from a practical project that to design a monitor and control system for the greenhouse. The content includes monitoring internal and external environment factors (such as temperature, humidity and so on), according to the environmental factor and the crop growth curve to control executable machines (such as windows, motors and so on). The goal is to make the crop grow in the optimal environment. Sensors, controllers and machines consist of the embedded system. Distributed sensors and controllers constitute the sensor networks. In the last chapter, the wireless sensor networks technology is discussed, also as upgrading scheme of this subject.