Fast talk

3 min read

The message from next month’s shows at the NEC is that the drive towards quicker and easier communication between intelligent components is on in earnest. Colin Carter reports.

Twenty years ago engineers checked individual fixtures by taking readings and making the necessary adjustments to ensure products came out ‘on spec’.

Now that machines have taken over much of the drudge of manufacturing and are offering cost-effective solutions in all areas, the major challenges are to build devices and plants that operate without large-scale human interaction, and making them and their components smarter by communicating better.

Of course, everyone has had their eyes on industrial fieldbus protocols, and the seemingly never-ending wrangling over an international standard that has still to properly materialise. with a few exceptions, the European market leader across many industries seems to be the Siemens-backed Profibus consortium.

Visitors to MTEC, Machine Building, IPOT and the other related shows on 15–16 February can see a demonstration of modern fault-finding tools on a working Profibus network, as well as a new multi-vendor demonstration system designed, built and operated by the team from the Profibus Competence Centre at Manchester Metropolitan University.

There are also notable industry groups that tend to use established protocols, such as CanBus’s dominance (automotive) and Echelon’s LonWorks in building control applications. Modbus also has firm support in industry.

One solution to the protocols challenge is the recent introduction of ‘protocol converters’ — often a ‘black box’ capable of connecting devices to any type of network with a bit of software tweaking. Typically these sit between the field device, connected by a serial interface, such as RS-232, RS-485 and RS-422, and can link, for example, Modbus devices to a Profinet — high-speed industrial Ethernet — network. Perhaps not the most elegant solution to the lack of a world standard, but a solution nonetheless.

There is no doubt that end users are adopting fieldbus systems more and more. The most recent evidence of this comes in a report by the ARC Advisory Group in November 2005, which set out to examine general process automation trends over the last couple of years.

One of the major trends identified is the number of mission-critical applications now using fieldbus systems. This is considered to be a good measure of an increased confidence in the reliability of fieldbus. In 2003 only four per cent of those surveyed by ARC used fieldbus systems for mission-critical applications. In the 2005 report this had rocketed to 28 per cent.

Perhaps one of the reasons for this is the development of Ethernet systems, such as Profinet. the adoption of familiar, tried-and-tested, Ethernet networks in industry has seen an explosion in the number of Ethernet-ready devices available.

One of the drivers for this is the opportunity to derive real-time (or near real-time) information for more efficient condition monitoring, with much of the processing possible at device level now. Also, according to the ARC report: ‘Ethernet’s ubiquitous IP addressing and routing capabilities enable a level of transparency never seen before in what was previously the domain of industrial networks.’

There is no doubt that Industrial Ethernet is here to stay. As Dr Volker Oestreich of the Profibus International (PI) support centre recently said: ‘Industrial Ethernet is now used as standard in the process industries as a system bus [in the coupling of process control systems] and in client-server architecture at the HMI level. Today’s solutions, such as Profinet, will play a major role in the process industries in the future. Profinet will take on the function of a fast backbone bus and communicate with existing fieldbuses via standardised gateways.’

Mark Crocker of Baldor, which is exhibiting its ‘Ethernet Powerlink technology’ at the Machine Building show— echoed these views. ‘We are seeing a great interest in real-time Ethernet devices from our customers. The market is very much expanding and we are looking at huge growth in 2006–07 as the technology comes to market.’

Regarding future developments Oestreich was upbeat, noting that work by Profibus was continuing. ‘We expanded our Profibus PA device profile by diagnosis options (Condensed Diagnosis) and by security-oriented communication (Profisafe for PA).’

Network security is also a big issue for industry — something that, according to Oestreich, has been addressed. ‘With the increased use of Ethernet in the field, wireless LANs in automation, remote services via the internet and the networking of automation areas using office LANs or company-specific intranets, the security issue must be taken seriously,’ he said.

To counter any possible security breaches PI has produced ‘Profinet Security Guidelines’ and a broad security initiative with other industry groups with a view to pointing the way to a ‘secure future of Ethernet-based automation networks, including the process industries’.

It’s clear that with the backing of groups such as the Profibus consortium, which currently has over 50 active working groups working on Profinet, that Ethernet networks will become commonplace as the network of choice for engineers. Oestreich elaborated further, particularly in respect of the integration of Profibus PA and integration of HART, which are being pursued as high priorities.

Of course, Profinet is not the only industrial Ethernet solution available. Baldor’s stand is testament to this, featuring demonstrations of its Ethernet Powerlink compatible machine controller and servo drives. This will illustrate the simple migration route the technology offers for motion automation builders currently using positioning drives compatible with the CANopen DSP 402 standard.

‘Machinery OEMs can start to employ dual-standard DSP 402/Ethernet Powerlink drives in their equipment immediately, while they port their control system software to a new generation core and take advantage of the new Ethernet environment,’ said David Greensmith of Baldor. ‘A phased changeover makes it easier to upgrade, allowing machine evolution to happen in predictable and manageable steps.’

So it’s clear that progress is happening at an amazing pace. The next generation of machines is already incorporating industrial Ethernet for its speed, capacity and determinism. And, over the medium term, it’s sure to become more commonplace.