Design And Implementation Of WirelessHART Protocol Stack

WirelessHART is the first open industrial wireless network protocol speciallydesigned for wireless communication application in process industry. WirelessHARTprotocol is reliable, real-time, secure and simple. It can replace wired network to somedegree, and provide convenient real-time monitoring, diagnostic, and control servicesfor process industry, which will play a significant role on reducing cost of processautomation and improving productive efficiency.This article gives design and implementation of WirelessHART procotocl stackbased on WirelessHART specification and wireless communication demand fordevices vibration monitoring application. First, Application requirements and a typicalWirelessHART network are analyzed, and then the architecture of monitoring networkbased on WirelessHART is designed. It is composed of the following component,including WirelessHART node, network access point, gateway and backgroundmonitoring software, in which the protocol stack implementation is core of thisarchitecture. Then, this article mainly gives design and implementation ofWirelessHART network manager, datalink layer and network layer. Practicalimplementation is based on Mega128, CC2420hardware platform and TinyOSsoftware platform, and physical layer implementation of IEEE802.15.4is used in theimplementation. Network Manager is responsible for routing, communicationresources scheduling, and time synchronization management. Routing managementmaintains the mesh network topology, establish, update, and distribute routing table;communication resources scheduling management allocates time slot and channel ofthe whole network; time synchronization management designs dynamic choose methodof clock source and the synchronization method among all the clock sources. TDMAcommunication is realized in datalink layer. Routing and reliable communication is innetwork layer, including graph routing, source routing, proxy routing, and reliable endto end communication. Also a simple application layer, gateway, and backgroundsoftware are implemented to support overall test. Application layer interact withvibration sensor through IIC connection; gateway connect WirelessHART network access point with Ethernet; background software shows network topology and providescommand for user to control the network.The WirelessHART protocol stack is tested in hydroelectric power station,laboratory, and campus, including mesh network formation test, data communicationtest, packet lose rate test, and end to end delay test. This WirelessHART protocol stack,together with vibration sensor and background monitoring software, can form devicevibration state monitoring system. And better WirelessHART network and applicationcan be developed on this basis.