Automation controllers and IoT connectivity

19 May 2020

Today’s automation systems are expected to deliver an increasing amount of data about every aspect of their operation and performance. The Internet of Things (IoT) provides, in principle, an attractive way of meeting these requirements, but how can IoT concepts be implemented easily, reliably and cost-effectively in the real world?

Nick Rhodes, Electronics & Automation Team Leader at Weidmüller UK, has the answer.

The thirst for data collected from automation systems is easy to understand. Detailed information about every aspect of plant performance right down to sensor level, when properly analysed, makes it possible to implement effective preventative maintenance programmes, to identify areas for efficiency improvements, and to spot negative trends so that they can be addressed before they become problematic. In a nutshell, data from an automation system can help to cut costs, improve productivity and minimise downtime.

Providing all of that data does, however, pose something of a headache for the automation system designer. Almost all modern automation systems have at their heart one or more programmable controllers (PLCs), but the problem is that PLCs, as their name suggests, are primarily designed to provide control functionality rather than to collect and curate data from multiple sources, then deliver it in a readily useable form – all of which are key requirements for an effective IoT implementation.

On the other hand, using one system for control and another for data collection would massively increase complexity and cost. It’s clear that what’s needed is some way of integrating PLC and IoT functionality, but this brings challenges of its own. Specifically, the PLC functionality requires a fast, deterministic real-time response and this must never be compromised by tying up resources to provide the IoT functionality, which is not required to operate in real time. Fortunately, advances in hardware have made possible a very effective solution: automation controllers have recently become available that use dual-core processors, with one core dedicated to providing the PLC functionality while the other independently handles the IoT tasks.

A further benefit provided by the best of these new generation automation controllers is that they feature integrated engineering tools for software development. Until now, almost all PLCs have been programmed using engineering tools that run on a laptop or desktop computer. These tools are proprietary, and the PLC manufacturers invariably charge licensing fees for using them. These fees are often substantial, and typically have to be paid annually to allow continuing use of the software.

The integrated engineering tools of the new automation controllers eliminate all of this cost and inconvenience at a stroke. Intuitive in operation and fully compliant with IEC 61131-3, the tools are accessed via a standard web browser. As well as making licence fees a thing of the past, this brings additional benefits. There is no software to download and there are no minimum hardware requirements for the device that will be used to access the tools. Whether it’s a PC, laptop, tablet or even a smartphone, if it runs a standard web browser, it can be used.

The best of the new automation controllers, when employed with compatible I/O systems, go even further by providing automatic identification of I/O modules. This reduces the time needed to develop programs and minimises the possibility of errors. It also makes life much easier if the system ever needs to be modified, as the I/O modules can be moved to new physical locations, as required, without the need to make any changes to the software.

For visualisation of the data collected by the controllers and to provide plant operators with local control facilities, the new controllers offer full compatibility with traditional HMI units, but their web-based technology means that they also offer another interesting option. They can be configured to send data to and receive operator inputs from almost any smart device, such as a tablet or smart phone. In many applications, this is an extremely useful feature, as the plant operator is not tied to a particular location – they can walk around the plant, taking their tablet with them, and still be fully informed and in full control.

When it comes to IoT functionality, these new automation controllers offer features that are equally impressive. They have integrated programming tools based on Node RED, which is open-source software designed specifically to provide “low-code programming for event-driven applications”. Widely seen as the preferred platform for IoT implementations in the automation sector, Node RED can be used for simple tasks such as mapping variables from plant devices into data storage locations and the elements of web-based displays, as well as for much more complex tasks which are made easy by the huge and fast-growing library of Node RED function modules.

For making the data available externally, the new automation controllers have built-in servers for OPC UA, which is a popular open-source protocol that has been specifically developed and optimised for communicating with and collecting data from industrial equipment and systems. This protocol is supported by almost all major equipment manufacturers in the automation sectors, so its use ensures broad compatibility and a high level of future proofing.

Much is currently being said and written about the IoT in automation applications and with good reason. The data it makes available is the key to making processes and systems more productive, more reliable and more profitable. And, as this article has hopefully shown, accessing the benefits of IoT doesn’t have to be a complex or costly enterprise.

The new generation of automation controllers, of which products in Weidmüller’s u-control 2000 range are leading examples, mean that the cost of an automation system with full IoT capabilities is little, if any more than the cost of a similar system without those capabilities. If your work involves purchasing or specifying automation systems, you might want to bear this in mind!

For more information visit www.weidmuller.co.uk, or email marketing@weidmuller.co.uk