WirelessHART- Implementation andEvaluation on Wireless SensorsDAVID GUSTAFSSONMasters’ Degree ProjectStockholm, Sweden April 2009XR-EE-RT 2009:003AbstractThe process automation industry is adopting wireless technologies, but in suchharsh environments technologies like Bluetooth and ZigBee are not reliableenough. An alternative to Bluetooth and ZigBee is WirelessHART that cancope with the noisy environment but instead imposes very high demands on thehardware. We show that it is possible to run WirelessHART on sensor nodeswith as little as 10 kilobytes of RAM and a processor running at 2.46 MHz.This is the first major step towards an open alternative to the proprietaryimplementation of WirelessHART.iiiAcknowledgementsThis thesis has been performed in the Networked Embedded Systems group atSICS. I would like to thank my main advisor Niclas Finne from SICS for hissupport and all the fruitful discussion we have had. I would also like to thankmy advisors Thiemo Voigt from SICS, Mikael Johansson from KTH and TomasLennvall from ABB for their support. Additionally I would like to thank thewhole NES group for their support and for making this a very enjoyable time.I want to dedicate this thesis to my family and especially my mom and dadfor their never-ending love and support.This thesis has been performed within the SICS Center for NetworkedSystems funded by VINNOVA, SSF, KKS, ABB, Ericsson, Saab Systems,TeliaSonera and T2Data.vContents1 Introduction 11.1 Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 Alternative Approaches . . . . . . . . . . . . . . . . . . . . . . . 21.4 Scientific Contributions . . . . . . . . . . . . . . . . . . . . . . . 21.5 Thesis Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Background 52.1 Wireless Sensor Networks . . . . . . . . . . . . . . . . . . . . . . 52.2 The Contiki Operating System . . . . . . . . . . . . . . . . . . . 52.3 Industrial Process Automation Protocols . . . . . . . . . . . . . . 72.3.1 HART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.3.2 WirelessHART . . . . . . . . . . . . . . . . . . . . . . . . 92.3.3 ZigBee PRO . . . . . . . . . . . . . . . . . . . . . . . . . 112.3.4 6LoWPAN . . . . . . . . . . . . . . . . . . . . . . . . . . 122.3.5 ISA100.11a . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Design and Implementation 153.1 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153.1.1 Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.1.2 Callback Functions . . . . . . . . . . . . . . . . . . . . . . 163.1.3 Final Design . . . . . . . . . . . . . . . . . . . . . . . . . 173.2 Code Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173.2.1 Network Layer (whnet) . . . . . . . . . . . . . . . . . . . 173.2.2 Transport Layer (whtrans) . . . . . . . . . . . . . . . . . 183.2.3 Communication Table Storage (session) . . . . . . . . . 193.2.4 Pool of Packets (packetpool) . . . . . . . . . . . . . . . . 203.3 Handling of Commands . . . . . . . . . . . . . . . . . . . . . . . 203.4 Communication Tables . . . . . . . . . . . . . . . . . . . . . . . . 203.5 Joining a Network . . . . . . . . . . . . . . . . . . . . . . . . . . 223.6 Routing Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . 223.7 Packet Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.8 Remaining Work . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 Evaluation 254.1 TMote Sky . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254.2 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254.2.1 Simulated Experiments . . . . . . . . . . . . . . . . . . . 26viiviii Contents4.2.2 Experiments on Real Hardware . . . . . . . . . . . . . . . 274.3 Memory Footprint . . . . . . . . . . . . . . . . . . . . . . . . . . 274.3.1 Memory Consumption . . . . . . . . . . . . . . . . . . . . 284.3.2 Code Size . . . . . . . . . . . . . . . . . . . . . . . . . . . 294.3.3 Comparing Memory Footprint . . . . . . . . . . . . . . . 304.4 Time Slotted Experiment . . . . . . . . . . . …