Smart Machines & Factories
A decentralised approach to digitalisation
Published:  31 March, 2020

The Industry 4.0 vision of a smart factory where every component, every device, every system and every site is digitally connected via the cloud presents an enormous design and engineering challenge. Is there a simple way of achieving the level of standardisation and connectivity required without compromising on design flexibility? Smart Machines & Factories asked Andy Parker-Bates of Festo UK for his view.

Where are we currently on the road to digitalisation?

APB: Industry is currently in a state of transition, where the benefits of Industry 4.0 connectivity are beginning to take hold but the standardisation required at all levels is not yet fully realised. A key stumbling block can be finding a decentralised I/O system that can connect to any of the most commonly used networks in industry today.

PROFINET, EthernetIP, EtherCAT and Modbus are all used in Industrial Automation: but for system designers and machine builders this makes it difficult to standardise because their various customers specify different networks in their factories. The idea of standardisation becomes even more complex when we consider the different architecture levels. A machine can carry IO Link at the base layer, PROFINET in the middle automation layer and OPC-UA over Ethernet with the communication to the cloud.

What is being done to address these challenges?

APB: Work is already under way to develop common communication protocols for Industry 4.0. For example, Festo is currently participating in the FIND (future industrial network architecture) research project, which is working to develop the foundation for the industrial Internet of tomorrow, based on the latest network technologies from the fields of industrial automation, Internet and 5G communications.

What factors should be considered in developing a standardised approach?

APB: Any means of improving connectivity must not compromise other aspects – such as the ability to process big data at high speed. Preferably, the devices involved should also be discreet and flexible, allowing machine designers and system integrators to position them wherever they are actually required.

For the end-user, the enabling technology should be invisible and allow access to data through their PLC without the need for additional equipment or specialist training. For the system builder, the number of interfaces required to achieve such levels of connectivity needs to be kept under control. Space is always at a premium, so reducing the size and number of interfaces required to deliver digitalisation would be a major step forward. In addition, the positioning of communications devices throughout the system should not be constrained by physical considerations such as size or cable length.

What solutions are available now?

APB: Festo has recently introduced a new communication platform that integrates IO Link, high speed data transfer to the cloud and intelligent connectivity to the host PLC in one simple package. This combination of capabilities offers some significant advantages over existing alternatives for machine builders, system integrators and the end user. Offering genuine network neutrality, CPX-AP-I ensures that customers can maintain a standardised architecture and bill of materials, with all I/O seen as being on the host network – irrespective of the customer’s choice of PLC.

How does CPX-AP-I work?

APB: The CPX-AP-I decentralised IO system is based on Festo’s new Automation Platform and provides seamless connectivity from the field level right through to the cloud, making digitalisation incredibly easy. Essentially, it consists of a fieldbus module which will connect to networks such as PROFINET, PROFIBUS, Ethernet/IP, Modbus and EtherCAT, ensuring that customers can integrate the system irrespective of their host PLC of choice. Below this fieldbus module, the system then becomes standard and communicates on the Automation Platform.

What improvements can we expect to see?

APB: Unlike solutions based on IO Link, the CPX-AP-I is always synchronous to its host PLC. This enables higher productivity due to faster overall cycle times and delivers real-time system behaviour. This is made possible because the AP protocol, which is embedded on Festo’s own AP ASIC, is embedded directly on the silicon – enabling the system to achieve impressive speeds of 200Mbaud/sec on each of the ASIC’s three ports. To put this into perspective, that is twice the speed of equivalent industrial Ethernet based networks available today.

Does better standardisation bring simplification?

APB: The new system brings simplification at a number of levels. For example, it has the flexibility of connecting up to 500 different devices, each containing the ASIC, to the same network node. The ability to incorporate more devices using fewer interfaces makes system design simpler and more flexible. Modules available include digital I/O, analogue inputs, incorporating temperature measurement, IO-Link masters and – unique to Festo – pneumatic valve terminals with embedded connectivity. Integrating valve terminals in the system reduces the integration cost and complexity for customers. It also allows machine builders to avoid connecting hardwired valve terminals to remote I/O or adding costlier PROFINET or Ethernet/IP valve terminal modules. This reduces the number of devices required, simplifying installation and shortening delivery times.

Are further developments on the way?

APB: New diagnostic features will be required to fully realise the potential of the CPX-AP-I system. The Festo Automation Suite forms the basis for parameterising, programming and maintaining devices from Festo in a single software package, and a new plug-in for AP-I is available. It already features temperature measurement in every module, load voltage monitoring, cable length, webserver with smart functions/live diagnosis, re-addressing protection and TIA V15 auto detection and other capabilities such as a valve cycle counter and IoT connectivity will be added shortly. Future diagnostic tools are likely to include dashboards, cable quality monitoring, actuator position monitoring and I/O time stamping, to name a few.

What does the future look like?

APB: CPX-AP-I is not only a simple decentralised I/O system. It represents a significant step forward in the provision of decentralised digitalisation, moving beyond what has previously been possible with simple IO systems. The Industry 4.0 vision is driving the need for speed and reliability in the collection and sharing of big data, and this is likely to accelerate and drive further improvements in future: but this should not be at the expense of simplicity and flexibility of design which enables machine builders and system integrators to optimise connectivity in the smallest space practicable.