A programmable logic controller (PLC) is an automated decision-making tool that is commonly used in manufacturing sectors, such as chemical processing, pharmaceutical, automotive and aerospace.
Since the creation of the PLC in 1969, factories have become better connected as different components link to one another and to the internet.
Technological advances and the introduction of the Internet of Things (IoT) mean each device has many inputs, usually in the form of sensor readings.
Information relating to motor torque, electrical interference and magnetic force is constantly being fed back, so the PLC needs to be network enabled to process the information. Often, PLCs have a huge quantity of data to process, therefore require a higher bandwidth.
As PLCs become connected to more devices, they can be targeted by malicious software, as infamously demonstrated by the Stuxnet worm. IoT presents a risk of its own, so network security is vital.
The security of a PLC is not built by design. Any compatible code can run on a PLC, regardless of where it comes from, so the potential for infection from malicious code is large.
Manufacturing trends
Globalisation leads to multiple plants in simultaneous use, and so the need for data to be gathered and analysed grows. Supervisory Control and Data Acquisition (SCADA) systems are an existing solution that allows real time data gathering from PLCs in multiple plants.
However, there is not currently an existing technology that can be embedded into the PLCs themselves to allow for remote control. The next generation of PLCs has the potential to build on this to enable remote operations.
Future focus
Remote monitoring, virtualisation and real-time monitoring are three technologies expected to lead the development of PLCs.
There is potential to create a PLC that assists companies in the adoption of Industry 4.0 but manufactures and operators need to recognise and fight potential security issues and connectivity setbacks.
It might well be that the future PLC does not resemble the PLCs of today. However, a device which functions as a PLC will forever be essential.
