Augmenting traditional production line control with PC based monitoring

By linking production-line PLCs with PC-based data acquisition and analysis, vendors of high-volume, tight-tolerance products can exploit of the best attributes of each to achieve consistency and quality.

Technology has brought a lot of changes to the factory floor in the past few decades. One major aspect is the widening gap between the modern computers we use in the office and the equipment running PET and aluminium can factories. Consider, for example, the difference between legacy equipment PLCs in a 30-year-old bottle-plant and the high-tech kit at our desks, and even in our pockets.

In business terms, this means some plants are missing out on the full force of modern computing ability.

PLCs will remain an integral part of production. But it is through laptops and PCs, not to mention smartphones and tablets, that we have access to the vast array of software used for production planning, tracking, traceability, scheduling and data storage. Factor in also the PC's role in the numerous – and increasingly mandated – regulatory and traceability reports, and their importance in the factory system becomes even clearer.

For PET and aluminium can production lines, PC-based analysis and connectivity allows for far greater management insight into the production flow. By analysing key parameters such as wall thickness at critical points, colour, clarity, and surface gloss, container manufacturers can guarantee that quality and performance will be built in to the end product. In short, it makes management better equipped to anticipate problems, instead of arriving at them on the back foot.

PCs also allow for the addition into the information chain factors such as beverage market data, and the availability and pricing of raw materials such as plastics. Even individual production lines across a number of factories can be compared, with changes made to improve the performance of units that are lagging behind.

There's a flexibility benefit, too, as PCs allow for the accessing of data through smartphones and tablets - the possibilities for which are dramatic and wide-ranging (and, frankly, somewhat scary, too). 

Still, there is one concern that cannot be ignored - the need to bridge the gap between often outdated legacy PLCs, with their unique input and output requirements, and the latest computers and their ever-evolving interfaces.

Replacing PLCs is often not a viable option in existing facilities, nor necessarily desirable as only dedicated systems can oversee the speed and performance demands of the line. So how do we add PC functionality to installed legacy hardware and software, and remain open to the inevitable future requirements?

That question has led to the emergence of a new line of modules that specialise in integrating PLCs and PCs previously separated by years of technological change. One such link is the ED-588 from Brainboxes, a DIN-rail mountable, digital I/O-to-Ethernet module that includes both an Ethernet port and a legacy-friendly RS485 port.

The ED-588 can be configured, monitored and controlled using a Windows COM port driver, which enables legacy software support by providing an interface to the Windows operating system. Networking the older serial modules extends their life for many years, keeping costs low and investment returns high; beverage plant engineers don’t need to retrain to use these devices. The port is compatible with industry-standard PC packages such as LabView, MATLAB, and Agilent VEE so users can continue to exploit the benefits of their existing development and process-control systems.

The module can also deliver data directly to smartphones and tablets using Android or Apple operating systems, as well as to web browsers. System programmers can use application programming interfaces (APIs) to enhance and tailor the supplied code examples. These APIs span a wide range: C#, C++, PHP, javascript, and .NET, with more coming.

And as it is important not to obsolete the installed base while looking ahead, the ED-588 carries adapter modules that provide connectivity and protocol compatibility between older serial interface standard RS-485 and the ubiquitous USB connectivity port. This allows for PC-based operating management and supervision on PLCs in every part of the PET and can production line, from moulding to spraying to boxing.

The road ahead

As the PC increases its role in PLC-based production, modules such as Brainboxes' ED units will support plant managers who demand PLCs for production control, but who also want access to the system-wide, analysis-focused, and networked advantages PCs can bring. Choosing a module with PC and network interfaces and compatibility allows managers to keep their options open for the future, and whatever changes that may bring.

 

Most importantly, these modules are able to bridge the gap in technology that previously separated the worlds of PLCs and PCs. With them in place, all parts of the PET and aluminium beverage can production process can join in tandem, working together to cut factory costs and fine-tune end quality.

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