The importance of standard platforms in safety critical industrial applications - Embedded.com

The importance of standard platforms in safety critical industrial applications

This “Product How-To” article focuses how to use a certain product in an embedded system and is written by a company representative.

As safety and security issues continue to dominate discussions inall sectors of the electronics industry, their impact is perhaps beingfelt most strongly in the industrial control and automation, transport,and medical markets.

The electronics industry is multifaceted and complex, and while thispresents many opportunities it can also lead to a generalization aboutthe issues facing the industry's individual vertical markets. There isa trend within the industry that is impacting all its segments tovarious degrees. Rising concerns over safety and security are becomingthe driving force behind developments, a force that is counterbalancedby the equally strong need for convergence and consolidation.

Meeting the requirements of these trends can be difficult in anymarket sector but none more so than for the industrial control andautomation, transport, and medical sectors. Arguably these sectors areseeing a paradigm shift tantamount to the first industrial revolution;once largely a mechanical domain, the use of electronic automation andits associated control functions now dominates.

Where there was onceperhaps a simple red button directly connected to an electrical contactto be used in an emergency, the same red button now represents theinterface to a much more complex network of processors, sensors andactuators. Managing this paradigm shift without losing sight of thefundamental safety requirements can be difficult, particularly in amarket where change is constant.

Sectors in the industrial market are highly horizontal in nature andcan be further partitioned by specific applications, each with its ownunique demands. The transportation sector, for signalling and control,is clearly very demanding in terms of safety, while in medical there isan increase in the use of complex equipment for diagnostics, coveringX-rays, CT scanners, dialyses machines and so on.

Another important market segment is the energy equipment market.Recent events have highlighted the demand for new, alternativeenergies, energy efficiency and cost-effective control solutions forenergy plants. Common to all these segments is the need forcost-effective solutions, which is driving time-to-market down whileallowing the equipment builders, integrators and operators to focus oninnovation.

Other sectors seeing similar demands include process automation,where there is a lot more distributed control and a growing complexity,bringing new challenges in the flexibility needed to build and maintainnew factories or plants quicker and faster, while not compromisingquality and safety. Industrial control, for example, robotics, isadding differentiation while ensuring safe operations in areas such asincreased uptime by leveraging near field communication between therobot head and control unit. Historically these sectors were driven byfunctionality but in each of these areas, safety, security, quality,maintainability and cost-efficiency are now of paramount importance.

With the growing complexity of embedded software and theintroduction of new and emerging multicore architectures forconsolidation purposes, the overarching safety requirements in thebasic functional safety standard IEC 61508, applicable to all kinds ofindustries, and its derivatives are driving new challenges to complyand still meet functional requirements.

Suppliers in the industrial market, as in any other, are beingpressured to deliver more for less. Consolidation and convergence oftechnology are the normal routes to cost reduction; however, forproducts that need to demonstrate compliance with IEC 61508, this canraise certification issues. This can subsequently increase the cost andtime of placing a revised product in the market. Another trend is thedemand for more connectivity, both wired (Ethernet) and wireless(Bluetooth, WLAN), meaning more complexity and interoperabilitychallenges in terms of the communication stacks required.

The challenge facing the industrial market, therefore, is how tocontinue to deliver cost reduction and feature enhancement throughconvergence and consolidation of technologies while remaining compliantwith growing safety requirements. Compounding the issue, the market hasa huge installed base of legacy applications, which require maintenanceand feel the pressure to innovate.

There is a real window of opportunity for all suppliers in theindustrial markets to leverage new technologies that will enable theconsolidation of functionality providing all the security, control andsafety capability necessary. Using the latest hypervisor concepts,combined with emerging multicore architectures, suppliers are now ableto combine multiple operating systems on a single, safety-compliantaggregation platform, providing a stable platform that returns both areduced bill of materials and increased functionality and flexibility.Now is the time to adopt a technology road map that will enable futureconsolidation and convergence without jeopardizing compliance withsafety and security standards.

As this happens, the quality of software is becoming much moreimportant. Separation concepts, allowing maintainability on one handand innovation on the other, enable suppliers to keep pace with newmarket requirements but are already challenging development andcertification processes. Due to the faster introduction of newfeatures, certification of safety software is changing from a”proven-in-use” model to a more formal tools-oriented model.

This isperhaps the biggest shift in this market, leaving developers unsure ofhow to approach these changes and how to know that their investment insoftware and associated tools will ensure certification while extendingto third-party software components.

In short, software complexity isincreasing and as a result its profile in industrial automationapplications is rising. Therefore, the demand for integrated, flexibletools environments with good multicore and multi-OS support will becomea significant differentiator for project success.

Existing solutions in these markets will typically apply hardwarepartitioning to keep safety-critical components and functionalityphysically separate from the non”safety critical, for instance, byusing a single-board computer for each part. As well as cost, otherdisadvantages of this approach include the need to maintain multiple,complete and separate systems, where different hardware and themaintenance of those hardware solutions increases both capital andoperational expenditures. In fact consolidation is now taking place notleast because distributed platforms represent a greater risk in termsof safety, security and complexity.

The role of embedded software is shifting as a result of theincreased importance and focus on differentiation at the software layerand the ability to add safety and security features through software onstandardised hardware platforms. For example, the use of real-timekernels in programmable logic controllers is now commonplace.

However,convergence and consolidation is occurring further up the value chain.The mentioned markets are counting on software to provide an overallenvironment for safety, security and connectivity. These are thecustomers who are in a position to consolidate functionality but alsoneed a lot of support at the software layer. It also means the issuesof safety and security are able to move up through the value chain,creating the need for more strategic engagements and partnerships withsuppliers of embedded software development tools, operating systems andmiddleware.

Enormous opportunities
Those consolidation concepts offer equipment manufacturesenormousopportunities as the openness of those frameworks enables theaggregation and smooth integration of a variety of subsystems, whichwill enrich the overall supply-chain dynamics.

It is important to appreciate the commitment necessary whenaddressing this market; the design cycle is typically two to threeyears, with a shipping cycle of up to eight years and a need forgreater than 10 years' support. This life cycle, already up to 20years, is under pressure to be extended further through more frequentupgrade programmes, demanding greater support from suppliers. Devicesoftware firm Wind River is helping customers to overcome these andother challenges, such as protecting their market share, theirintellectual property and their time-to-market, while reducing thetotal cost of ownership.

A modular software approach, for instance, helps with time-to-marketissues but raises the problem of paying to repeatedly certify elements,such as a UDP stack. Through modular certification, standard softwarecomponents can be delivered as part of a certification package.Customers can then rely on this evidence package for certificationagainst IEC 61508, allowing not only a faster approvals process butalso greater flexibility at the design phase and more predictability inthe business.

Consolidated platforms will drive the need for a variety of OSplatforms. Operating systems will be used more and more in a bestpractice method. Real-time operating systems have a greater advantagewhen considering determinism and less complexity compared to anon-real-time OS such as Linux, which makes them the ideal candidatefor certification.

Linux, on the other hand, has advantages whenimplementing rapidly evolving communication standards or graphical userinterfaces. It would therefore make sense to use both on the samesystem to leverage each one's success, to get the best of both worlds.Using a consolidation technology such as a hypervisor, this becomes areal possibility.

With many machine manufacturers now looking at using Linux, theissue of support arises. Here too there is some consolidation oftechnology, with better development tools, but there still exists agreat deal of fragmentation in the market for Linux-based solutions.Too often manufacturers attempt to cobble together free Linuxdistributions instead of choosing a supported and validated commercialdistribution.

<>Underestimated challenges
The complexity of Linux and the business challenges are totallyunderestimated. Training on Linux, stability of the distribution, openstandard compliance, indemnification, documentation and scalability arejust some of the benefits of choosing a professionally manageddistribution and should therefore be considered during the decisionprocess.

An important part of using Linux, for industrial customers, is theability to partition safety and non-safety-critical elements of thesame application on a single hardware platform. Linux provides highpotential for features and innovative middleware, which often adds alayer of complexity if safety is required. Hypervisor technology makesit possible to consolidate Linux and real-time operating systems at thesoftware layer, allowing safety and nonsafety applications to run onthe same hardware platform. Multicore processor technology, togetherwith hypervisors, enables multiple operating systems to runconcurrently on the same hardware platform but in partitioned,protected spaces.

Wind River offers its set of VxWorks platforms for industrialdevices. Through the addition of hypervisor technology, safety criticaltasks can operate under VxWorks, with communication protocols runningunder Linux and perhaps another operating system providing supervisoryfunctions on the same machine. legacy applications

The concept of hypervisor technology also enables simpler porting oflegacy applications. As under a partitioned architecture, differentversions of the same operating system can run simultaneously.Appropriate enabling and integration services help customers take therisk out of safety and consolidation projects by guaranteeing a smoothand predictable rout to market, with significant time-to-revenueadvantages.

A consolidated Eclipse-based toolchain further supports the trendtoward multiple operating systems, allowing applications targetingdifferent operating systems to be developed at the same time in thesame environment. This is a huge benefit to development teams. Theopenness of the Eclipse framework, allowing other tools to beintegrated with it, is now becoming key to machine developers.

The environment for machine manufacturers is undergoing arevolution; where once functionality drove innovation, nowcost-efficiency, time-to-market, safety and security are becoming theoverriding requirements. Convergence and consolidation will see morefunctionality being ported to cost-effective hardware platforms,demanding even more from the software.

Jens Wiegand is general manager for industrial solutions at WindRiver.

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