Automation systems have changed almost beyond recognition in recent history, and certainly not just in terms of the scope and sophistication of operator screens. Or, for that matter, the PLC, PC or DCS (distributed control system) hardware and firmware delivering the plant or factory monitoring and control.
You don't have to go back many years to a time when plant and engineering managers simply didn't talk to the folk in IT – and vice versa. Control systems relied on proprietary software (and hardware) built for determinism, robustness and reliability, but not so much with security and the web in mind. In contrast, office IT systems were designed to enable collaborative working in secure environments, but the odd frozen screen necessitating a restart was par for the course. So mixing the two disciplines was, rightly, an alien concept.
For those stuck on legacy automation systems, that remains more or less the case. But for others that have embraced modern technology, control systems are now close to indistinguishable from their office counterparts. That's partly because of a move away from proprietary networks to systems based on (although not identical to) high-speed Ethernet, even down to fairly low levels of the monitoring and control hierarchy. But it's also due to the adoption of mainstream IT architectures and concepts.
As Alan Norbury, central technology officer with Siemens, puts it, systems moved from centralised, hard-wired controllers to distributed intelligence with 'fieldbus' connectivity (such as Profibus, based on RS485). "Now, networks are Profinet, Ethernet/IP or some other manufacturing-centric derivation of Ethernet [with real-time, deterministic capability]. And Ethernet ports and built-in web servers are common," he explains.
Mainstream IT
Mike Oakley, ABB's integrated operations team leader, adds that from a control system perspective, changes have included the adoption of standard techniques, such as virtualisation of the server environment (sharing functions across fewer boxes), to maximise hardware utilisation and functional efficiency. Now, SAN (storage attached network) technology is enabling secure, lower-cost remote HMIs.
It's a similar story on I/O, with Emerson Process Management in the lead following the launch of its CHARMS (characterisation modules) 'I/O on demand' approach two years ago. The objective in that case was to ease project development, by allowing system builders to leave I/O details to later in the cycle, while also reducing cabinets, and simplifying the I/O and marshalling design process.
Common databases, common networks, common standards, common programming environments, common I/O... "Five years ago, 80% of project implementation was system configuring: now 80% is automated," states Oakley. "All the information for your database and tags comes in electronic form, and the system automatically generates the control system data structures from that." It's not just about saving time, he points out, but also reducing errors and enabling faster updates when required.
Additional benefits range from 'safe' internet connectivity to economies of scale around hardware, software and skills. The former enables, for example, remote, wireless and mobile access to systems – and all that means, in terms of improving both management understanding and manufacturing agility. The latter allows developers and users alike to harness familiar software tools – everything from Internet Explorer (IE) to drag and drop, etc. On the one hand, that speeds up system configuration, integration and change management, while on the other it brings businesses closer to production, without compromising plant safety.
"So, you can plug a PC into the industrial network and, if you have the rights, type in an IP address and access a drive, HMI or whatever, and gather information, using IE, for example," comments Norbury. "Similarly, a machine builder can ship his equipment anywhere in the world and monitor its performance remotely to diagnose and solve problems."
Cyber-physical manufacturing
And that's just the 'easy' stuff. The current order of automation systems also enables what the future gazers call cyber-physical manufacturing, Industry 4.0, or the fourth industrial revolution. The challenge is helping manufacturers to migrate from the systems they run now to those capable of agile manufacturing. And that's one of the tasks of the government-funded High Value Manufacturing Catapult and particularly the Advanced Manufacturing Research Centre in Sheffield.
Norbury describes its role as working with users to demonstrate the benefits of connected systems, while also de-risking the required leap of faith. Chief among techniques being used is virtual reality, not only to 'prototype' products and production lines in the virtual world, but also to show the power of live insights from data, ranging from energy consumption (including when not producing) to machine condition monitoring. It's a little way off, but it's coming.
Returning to the here and now, however, Emerson sales manager Johan Selinder points to the benefits of mobility enabled by modern system standards. Citing a wastewater utility on an unnamed metals plant, he says that nuisance call-outs have been eliminated since providing maintenance workers with 4G-connected iPads. "The plant is only manned during office hours so false alarms at night were costing a lot of money," says Selinder. "Now, engineers can log on remotely, using their iPads, and make decisions about whether they need to go in or not."
He says that mobile technology paid for itself within a few short weeks. And he adds that the plant has since taken on more iPads for roving workers (rubber-shrouded, in place of field HMIs) – that choice being about retaining the resolution of the existing graphics consoles and so saving development and upgrade costs. Once PDAs certified for Zone 2 and, even better, Zone 1 hazardous areas, are developed, the sky will be the limit for mobile HMIs in the chemical industry. For the rest, it's available now.
How quickly mobility will catch on in the conservative process industries – where sites tend to be large, so the benefits greatest – is anybody's guess. If it follows progress with wireless process transmitters, then, ready or not, we're in for a long wait. Selinder reckons that, although the latter has been properly available for five years – and offers huge cost savings where retrofit installations are concerned – it's only in the last 12 months that plant managers have started seriously considering wireless infrastructures.
University challenge
Just over two years ago, ABB invested close on £1 million in Imperial College London, installing one of its 800XA distributed control systems, along with associated instrumentation, motors and drives to manage the university's pilot carbon-capture plant, which boasts two 12-metre columns and associated equipment. In that time, no fewer than 5,000 people have seen the control room, with visitors ranging from school children to the president of Singapore, although it is primarily for chemical engineering undergraduates.
What does the system look like? Paul Dickens, who is ABB's link man into Imperial, explains that it was designed as a combined process control and safety system, with two independent, but integrated, processors on a virtualised server. The control logic itself runs on ABB's DIN rail-mounted AC800M modular controllers with 250–300 field instruments attached, most of which are analogue (temperature, flow, etc), although some are digital.
"We're running pretty much all of the commonly used transmitter protocols, from 4–20mA to HART overlays, Profibus PA and DP, and Foundation fieldbus, as well as Wireless HART," says Dickens, making the point that this is a teaching facility. As for the HMI workspace, that spans two screens, providing interactive graphical plant representations, as well as alarm and events summaries, with the usual facilities for zooming to instrument faceplates, etc.
For the students, the system has been set up to allow diverse column control strategies, up to selected predictive PI controls, with monitoring via the different instrumentation types – although the safely system (built to IEC 61508) is locked down. Equally, although plant start-up and shutdown are automated, the system has been configured to provide step-by-step visibility of the sequences.
Meanwhile, Dr Colin Hale, senior teaching fellow in the Department of Chemical Engineering at Imperial College, has more privileges and can inhibit alarms, force signals, etc, for teaching purposes. He says the system software was upgraded last year to the latest version (v5.1) FP4 (feature pack), providing enhanced alarm visualisation and management. "It now shows aspects such as longest standing alarms and their severity, and alarm response navigation has also been improved.