This solutionallows machine builders to easily adapt or expand their future designs based on one automation platform with a modular approach without having to change their original design. Modularity also typically saves 5% on hardware.

CPX-AP-I was recently incorporated by a machine builder into his design for a machine that finishes plastic sheet parts. These are mostly pre-shaped parts that are relatively long and narrow. Cut-outs are created in them by punching units. This is done pneumatically. Since not all sheet metal parts are the same thickness and they are sometimes also made of different plastics, not to mention shaped differently, the pneumatic pressure required must be set differently for each product and each cut-out. This was originally done using proportional pressure control valves that were controlled directly by the PLC.

From centralized to decentralized

The corresponding design of the machine had some disadvantages related to the central control of the pneumatic punching units. Eight proportional controllers were integrated directly into a central valve manifold in the control cabinet. Four punching movements took place at a relatively short distance from this valve manifold - 3 to 5 meters - but the other four took place on the opposite side of the machine. For these four punching units, cables and air hoses with lengths of 10 to 12 meters had to be laid from the control cabinet. In addition to the high material and installation costs, this also meant less accurate control of the rear four punching units as well as a longer cycle time.

When the machine builder in question received an order for four identical machines, he consulted Festo - as his technical partner - about the possibilities that new technologies could offer. Faster, better, more durable, cheaper? The new CPX-AP-I emerged from these discussions as a possible solution for decentralized control of the punching units and also to make the machine 'future-proof'. But there turned out to be many more advantages.

It shows that valve terminals and I/O-Link® masters can be integrated directly into the higher-level control system (PLC) regardless of the industrial automation network used. The same goes for both pneumatic and electrical modules and all known field buses are supported. This means that the valve terminals no longer need to be connected via an I/O link® Master, but can be controlled directly via the AP bus, which results in better performance in terms of reliability and efficiency. In addition, this means a saving in the number of bus nodes or components.

Modular structure in a familiar environment

The CPX AP-I offers the possibility of a modular, and therefore easily scalable, design. Adding or removing functionalities, modules, etc. is possible without the need to modify the existing topology. Changing the bus system is also possible by only modifying the bus node. The bill of materials (BOM) and control architecture are fully retained. Furthermore, machine builders can continue to program in their familiar environment and are in no way affected by the fact that the I/O system works with a proprietary bus system. They arecertainly not limited in terms of numbers, since up to 500 modules can be linked in line, star and tree topology.

Ready for digitalization in the age of Industry 4.0

In addition to the fact that the CPX AP-I can easily integrate components, it also offers the possibility of sending data to the cloud. This is a typical feature that fits into smart industry and fully automated smart factories. It means that a wide range of data, for example short circuits, IO-link® events, number of circuits, cable quality, temperature, voltage, operating hours, etc., can be collected centrally. This data can then be analyzed and converted into valuable information in the context of optimization, cost calculations or, for example, 'smart maintenance. It makes it possible to monitor various modules and the channels and to give an alarm in time if things threaten to go wrong. Moreover, it enables efficient maintenance planning as well as steps towards predictive maintenance.

Application in practice

The machine builder who started this story switched to the CPX AP-I on Festo's recommendation and has now literally seen the benefits with his own eyes. Due to the decentralized design, the group of eight proportional pressure regulators is now divided into two groups of four. The second group is placed on the other side of the machine and is therefore much closer to the punching units. This ultimately saved so much installation time and material that a cost saving of 5% was achieved when four machines were built. He was also able to offer his customer lightning-fast communication for all the modules that do not use IO-Link®. The figures of 200 MBaud and cycle times of up to 250 µs are impressive. Because two separate cables are used for communication and power supply, he also has the option of working with voltage zones if necessary. In the end, he was grateful that he could keep his existing topology intact. It can easily integrate valve terminals without the need for additional bus nodes or I/O Link® Masters. The number of interface modules is also limited due to the large number of components that can be linked to a CPX AP-I bus module.

Ready for the future

The machines have now been delivered and are running smoothly. To be more precise, they are running so well that the machine manufacturer has made the new remote I/O system the standard for all new machines that it plans to develop and build in the future. Other systems will only be used if customers explicitly request different specs. That goes the automotive industry, packaging machines and otherwise. "This is exactly what we need," was the final verdict of the (satisfied) machine builder.