British system simplifies controls by breaking them down

A small British company has developed a modular, distributed control system, based on intelligent networked controllers, which, it claims, will cut the complexity and costs of applications such as conveying and handling.

Derby-based Intelligent Distributed Controls (IDC) says that, by doing away with a central PLC, its Simplicon system (shown above) overcomes the growing complexity of control software. It allows even the most complicated machine sequences to be broken down into simple, separate control tasks, each handled by its own processor dedicated to a section of plant or a mechanical sub-assembly.

The system is the brainchild of IDC`s managing director, Kevin Buckley. "There are lots of PLC vendors offering distributed control products," he explains, "but they are too expensive, considering the separate processor, power supply and communications modules needed for every section of a conveyor system.

"There are also alternative brick-type PLCs with remote distributed I/O cards," he adds. "These products would be economically viable, but they do not provide peer-to-peer communications, which enable interlocks and sequence signals to be sent between nodes - essential for an intelligent, distributed architecture."

Another problem with previous technologies, according to Buckley, is that they rely on software tools that have to cater for a wide range of applications and are designed for single-processor platforms. "What`s needed are software tools designed for a multi-processor platform, which are also easy to configure and link together, effectively deskilling the whole operation," he argues.

IDC has worked with university researchers to come up with its alternative. "Because most conveyor applications can be broken down into simplistic operations, we have opted to use proven, high-speed, low-cost eight-bit processors," Buckley continues.

He regards the system`s Windows-based, IEC 61131-3-compliant software as probably the most important element in the Simplicon system. "It enables the realisation of single cells associated with individual tasks, naturally breaking down the complexity of the machine, and making individual programs easy to maintain," he says.

"What makes Simplicon both different, and superior to, existing technology is not the obvious advantages of reduced cabling costs, or quicker installation time, but the hidden benefits that extend throughout the whole lifecycle of a project," says Buckley. These include: more accurate tendering and estimating; smaller and simpler programs; the ease of upgrading and extending installations; and the ability to build and test the mechanical, electrical and control elements before they are shipped.

IDC was formed a year ago by a team which used to work for the controls supplier Cotas, where Buckley was MD. Following Cotas` takeover by the Danish wind turbine manufacturer Vestas, its has focused on work for its new parent.

IDC has taken over many of Cotas` external clients and their projects, and this work has helped to finance the development of the Simplicon system. IDC has also received a £45,000 Smart award from the Government to help fund the work.

Buckley started work on the distributed control technology about four years ago, initially for use within Cotas. He hopes to start marketing the Simplicon system in the first quarter of 2004. Initial sales will focus on the UK, and manufacturing will be sub-contracted. Buckley already has plans to develop the technology further by, for example, adding analogue facilities.