535 Embedded Systems in Distributed Measuring Network Zygmunt Kubiak 1 , Andrzej Urbaniak 2 Abstract In the paper there are analyzed two important problems concerning monitoring systems: intelligent sensors and effecti- ve transmission. First part of the paper includes, for example, the description of new solutions for specialised pressure and temperature sensors. These sensors utilize the features of monolithic silicon. The measuring parameters of these sensors (i.e. measure range, sensitivity and repetitiveness) are very high. In the second part of the paper there are deve- loped several kinds of sensors’ network. The main interest is focused on the wireless network. The protocols imple- mented in these networks utilize usually only three layers defined within the OSI standard. There is developed the transmission standard (ZigBee) for sensors’ network. 1. Introduction Monitoring systems are usually used for evaluation of environmental quality. There are three main pro- blems that ought to be solved in monitoring systems, concerning sensors, transmission and visualisation tools. First problem focuses on functionality and quality of sensors applicable for environment’s quality monitoring. Effective solution of this problem can be found using embedded systems within the sensors. Nowadays intelligent sensors have brought new approach to the computer engineering. Moreover, the embedded systems mean new direction in computer technology and are developed intensively. Wide ap- plications of embedded systems are connected with increasing market of microcontrollers from one side and its decreasing price from the other. In many cases there are new physical phenomena applied in con- struction of the sensors. These phenomena have usually been known earlier but their implementation in sensors’ construction has been impossible without computer tools, thus they are named “smart” sensors or intelligent sensors. Very important second problem is connected with data transmission from measuring points to central computer. The choice of proper transmission medium must take into account special restrictions and in- dividual possibilities of the environment. Traditional wire transmission is usually impossible, for many reasons. Nowadays, there are given new possibilities with wireless communication. Necessity of commu- nication with different types of networks focused to prepare the new communication standard dedicated for these types of networks. Taking into account security and quality of data transmission, there are spe- cialised microcomputer systems applied for communication tasks. The embedded systems realise the ope- ration and transmission functions. The main operation functions realised by embedded system are the fol- lowing: linearisation of non-linear characteristics, signal standardisation, measurement verification and sensor testing. The transmission functions are connected with service of communication protocols. Many of these solutions are supported by the embedded systems with specialised communication software util- ising the new international standard dedicated for wireless sensor network. In many solutions there is used the specialized standard for environmental quality monitoring. Large measuring network is organi- zed in special configuration utilizing the measuring nodes knowing as MASTER or SLAVE node. Very important in these types of network is minimum energy utilization, thus the measuring node is usually activated for the very short time necessary just for the measure work. Rest of time is the “sleep” state. 1 Institute of Computing Science, Pozna University of Technology, e-mail: zygmunt.kubiak@cs.put.poznan.pl 2 Institute of Computing Science, Pozna University of Technology, e-mail: andrzej.urbaniak@cs.put.poznan.pl EnviroInfo 2007 (Warschau) Environmental Informatics and Systems Research Copyright © Shaker Verlag, Aachen 2007. ISBN: 978-3-8322-6397-3