wi-htest : compliance test suite for diagnosing devices in real-time wirelesshart network

Wi-HTest: Compliance Test Suite for Diagnosing Devices in Real-Time

WirelessHART Network

Song Han, Jianping Song, Xiuming Zhu, Al Mok

Deji Chen, Mark Nixon

Wally Pratt, Veena Gondhalekar

15th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS’09)

Outline

• Introduction and Motivation

• Wi-HTest Architecture

• Wi-Analys and Post Processing Suite

• Test Cases

• Conclusion


Introduction

• Overview of WirelessHART Project

• Motivation for Designing Wi-HTest

• WirelessHART Test Specification

• Test Script Format


WirelessHART Project Overview

20062007 2008 2009

WirelessHART Standard under development

First open wireless communication standard for industrial process control applications

UTCS and Emerson working on the first prototype WirelessHART stack



20062007 2008 2009

WirelessHART standards released in September 2007

* Secure and TDMA-based wireless mesh networking technology

* Operating in the 2.4 GHz ISM radio band

* Strict timing requirements, highly reliable and interoperable



20062007 2008 2009

Three WirelessHART-related Projects Launched

Wi-HTest Location-aware Application Network Manager



20062007 2008 2009

Wi-HTest released and available to member companies

Various WirelessHART devices are under testing


Introduction






Motivation for Wi-HTest

• No existing test suite for WirelessHART

• Assure the standard compliance of WirelessHART devices

• Need a tool to provide thorough tests for every layer of WirelessHART

• Help vendors avoid expensive product recalls and technical support costs


Introduction






Test Specification and Test Script

• 5 Phases on 4 Different Layers– Boot-Strap Tests– Single Correspondent Tests– Multiple Correspondent Tests– Multi-channel-selection Tests– Stress Tests

• Format of the Test Scripts– small, narrowly-focused test applications– test configuration + test body


Wi-HTest Architecture

• Overview• Wi-HTest Host Architecture

– RF Interface Driver– Network Layer Library and Virtual Device

• RF Board Design– Hardware Platform– Real-time Embedded Pseudo Stack– The Command Processor


Wi-HTest Host Architecture



Test Configuration

Configuration MSG



Test Body

Network Packets



Responses from DUT



Support NWK layer performance test

Support PHY/MAC header manipulation

Support NWK packet manipulation


NWK Layer Library on Host

• Why separate the network layer from the RF?– Save resource and guarantee stringent timing requirement on the

MAC layer operations.– More direct and convenient to inject fault data into the network

packet header and payload.– Provide the possibility and flexibility to simulate virtual devices and

form a simulated network.

• Functions in the Network Layer LibraryNetwork Layer Initialization Network Layer ConfigurationBuilding Interface Messages Encrypting and Decrypting

Network Packets Authentication Maintaining Communication Tables


Virtual Device

• Goal: – Form a simulated network and perform network layer test on DUT.

• Network Layer Design– Separated from MAC layer and installed on Linux Host– Independent session and corresponding table structures– Complete control over the network layer header/payload

• MAC Layer Design– Allocate necessary superframes and links for communication– Faked MAC packets and self-ACK between GW and VDs.– Normal MAC communication between VD and DUT.


Example of Virtual Devices


RF Interface Architecture

Pseudo Stack


Pseudo Stack and Command Processors

• Real-time Embedded Pseudo Stack• a streaming strategy to encipher a frame and decipher its ACK• The interrupt handler is kept as simple as possible• Give the MAC layer the highest scheduling priority

• Three command processors• Configuration Cmds: Cmd to configure the RF Interface.• Test Cmds: Cmd to be transmitted by the RF to the DUT.• Test responses: The responses from the DUT to the Host.


Wi-Analys and Post Processing

• Complete compliance verification environment needs another two supporting tools

• Wi-Analys – 16 WirelessHART Channel Sniffer– Display online messages or redisplay captured log file– Built-in intelligence to decipher the messages– Built-in filter to display selected messages

• Post Processing Suite– Check the sequence of the messages the DUT transmitted, the

transmission time points and the relationship of the messages


Snapshot of Wi-Analys

Channel Hopping

Built-in Filter

Deciphered Payload


Representative Test Cases

• Device Join Test (Application Layer)

• Superframe Management Test (MAC Layer)

• Source Routing Test (Network Layer)


Device Join Test


Device Join Test

Join Request with Unique ID

Write Key and Nickname

Write Superframes and Links


Superframe Management Test

• Test Sequences• Increase the number of superframes on DUT until its superframe

table is full. After that, add one more superframe.• Delete one superframe from the DUT and modify an existing one by

providing invalid number of slots.• Modify that superframe again with valid number of slots.• Add a new superframe with an invalid mode.• Delete two superframes from the DUT and then add another two, one

with an ASN in the future and one with an ASN in the past.• Delete all existing superframes on the DUT.


Superframe Management Test

The superframe table is full

The DUT reports error status

Try incorrect number of slots


Source Routing Test

The virtual device relays the network packets

Self-ACK

Response from the DUT


Conclusion

• Wi-HTest is the first compliance test tool for diagnosing WirelessHART devices.

• Wi-HTest supports packet manipulation and can conduct compliance tests for every layer.

• Wi-HTest, Wi-Analys and the post process suite form the complete compliance verification environment.

Smart Control Systems

Smart Analytical

Smart FinalControl

Smart AssetOptimization

Smart Safety

Smart Measurement

Smart MachineryHealth

Smart Wireless

Without the Limits of Wires….Imagine What You Could See and Do

wi-htest : compliance test suite for diagnosing devices in real-time wirelesshart network

Documents

embedded technology

ieee realtime

test scriptssmall

compliance test suite

wihtestno existing test

prototype wirelesshart

test script5 phases

diagnosing devices