Scaleable connection of remote I/O and valve terminals

"In-basket and out-basket, or 'basket loader/unloader'?" laughs Van den Akker. Whatever their latest construction is called - it is Apollo Engineering's latest automation project. The installation collects filled cans and transfers them to an autoclave for sterilisation, collecting them again on the return.

Van den Akker is one of the directors of the engineering firm based in the Netherlands and his colleague Lourens is one of his engineers. Lourens explains officially, it has been called a basket loader/unloader and that is how the installation will be documented when this interesting piece of Dutch technology starts its long journey to its destination, Ivory Coast. This could just as easily have been Indonesia or New Zealand because Apollo Engineering's clientele operates across the world.

Basket loader/unloader

As the name suggests, this machine is intended for filling and unloading baskets. The baskets are filled with cans that have contents needing to be sterilised for extended hygienic storage. This is done under pressure and with steam in an autoclave. When this process is finished, the baskets complete with cans are removed from the autoclave and the cans are unloaded.

Previously the handling was done manually by the end customer. Each can and its contents weigh roughly one kilogram, and a basket may contain up to 400 cans, stacked in layers with intermediate sheets, depending on the size. The customer thought this arduous process could be automated and having already had good experience working with Apollo Engineering, thought he would throw them the challenge; the automated basket loader/unloader was the result.

In the modular machine, the cans are automatically supplied via a conveyor belt. The cans run against a stop and once enough cans are collected for a complete layer, new incoming cans are stopped. The collected layer is then transported until the cans are aligned under an ingeniously concealed magnetic plate. Assisted by Festo pneumatic cylinders for the vertical movement, the magnetic plate picks up the complete layer and places it on an intermediate sheet in the ‘ready’ basket. The layer of cans is again covered with an intermediate sheet that is picked up and deposited using vacuum and so the process repeats itself until the basket is filled.

For the vacuum 'handling' of the intermediate sheets, the installation is equipped with an OVEM vacuum generator, which actively monitors the vacuum level with a built-in IO-Link vacuum sensor. The air-saving function switches off the compressed air as soon as the set vacuum level is reached. This keeps compressed air consumption to a minimum, potentially saving up to 80% compared to a standard vacuum generator.

Electrically driven traverse

Once the basket is full of cans, it is moved using a chain conveyor. This frees up space for the next basket, which is also supplied. But this does not yet take care of transporting the filled baskets to the autoclave - and out again. During the design phase of the project, Apollo Engineering carefully considered this transfer as dragging a filled basket is quite a heavy job. And for that too, a solution was devised in the form of an electrically driven traverse. The traverse is capable of transporting a 'train' of up to five linked baskets from the basket loader/unloader to the autoclave. After the sterilisation process, the traverse brings the baskets back to the installation.

Modular and decentralised construction

In addition to the machine placing cans in the baskets, the second function is to take them out again. This is done on the opposite side of the installation, where the steps are performed in reverse order. Although the structure differs in detail, we are actually talking about two functionally identical modules - with space in-between to buffer empty baskets.

Modular constructs are emphatically pursued by Apollo Engineering although Van den Akker admits that most designs need a degree of customisation and adaption to be used for another job. But he stresses, it does make it easier to build on. Directly linked to the pursuit of modularity is the application of decentralised I/O signal handling. Lourens is an absolute advocate of this, and this is also supported internally: "look at the conveyor that needs to be built into this job and how much nicer it is to be able to simply hook up and connect all the components including remote I/O. You can have all that pre-prepared and then all you have to do is connect it and you're done."

Keeping it as simple as possible

That saves a lot of cabling, says Van den Akker, which is confirmed by Lourens: "We are always thinking about how we can keep our builds as simple as possible. Sensors have to be cabled, there's no getting around that, but this is where the Festo CPX AP-I comes in."

Apollo Engineering has always used a lot of Festo's CPX valve islands. Its modular architecture allows it to integrate the bus node, remote I/O and valves in one modular component. You can therefore use these valve islands centrally and de-centrally and connect all your devices – inputs, outputs and pneumatic actuators directly to them. But was that the best technology for the basket loader/unloader?

Festo put the Apollo engineers on the trail of the new CPX AP-I decentralised I/O platform for this application, which flexibly and scaleably connects I/O modules and decentralised valve terminals from Festo to all common control architectures. CPX-AP-I technology allows you to build modular and decentralised, according to the size and layout of your machine design. Lourens attests to this, “with CPX AP-I, I can, for example, take two units and connect four sensors to one and two to the other. You hang them in the machine, couple them with the ready-made cables and you're done”. The VTUG valve islands in the basket loader/unloader also have the same internal AP bus as the CPX-AP-I platform, so they can be seamlessly and transparently incorporated into the system without any problem.

Van Akker also sees how the decentralised CPX AP-I platform supports Apollo Engineering's way of working. “In the field, it is really just a matter of linking and connecting the power supply. The various functional tasks of the machine can be fully prepared during set-up at Apollo Engineering with the necessary I/O terminals and valve islands. Cabling in the field is reduced to a minimum.”

Apollo Engineering is constantly looking for solutions to make life as easy as possible for their customers and themselves. Using the CPX AP-I platform is a first for them. Lourens became convinced of the added value of the system after a visit to the Festo Experience Centre in Delft and his discussion with the product specialists when the first concept sketches for the basket loader/unloader were underway.

That marks the level of mutual trust between Apollo and Festo Lourens explains. “You do transactions with a supplier, that's one thing, but create business with people". Van den Akker adds, "we work closely with the people at Festo and that's very important to us. We get good support, and they are always ready to help us and enthusiastic to come to us”.

This also makes Festo a great fit with Apollo Engineering which, as Lourens states, is not too big and thus has the ability to move quickly. And then your supplier has to be able to keep up. "The stuff is good too", says Van den Akker, laughing. "We always try to do good work so our customers stay with us. Our customers demand quality and we give them that - by only working with quality brands. Festo is a good example of that and we like the good contacts with the people behind the brand. It is an A-brand- full stop."

Apollo Engineering

At Apollo Engineering in Aldeboarn, in the Netherlands, you knock on the door for turnkey projects - from idea to realisation, installation, service and maintenance - as in the case of the basket loader/unloader. But they also do not shy away from pure engineering, both mechanical and electrical, and various packaging producers gratefully and often make use of it. They are also the importer and dealer for the Benelux of parts of packing machines and the grippers and suction cups of the Italian company Orobica Plast-Gom from the Bérgamo area. And that is less strange than it seems.

Not infrequently, the custom work Apollo Engineering delivers involves automation solutions directly or indirectly related to packaging - and especially in the food sector. This is more or less historical. In 1986, the company was founded in Aldeboarn by Marinus van der Meulen and Frits de With. Both have a considerable track record in designing packaging machines and decide to take the plunge into independent entrepreneurship. With success as they soon landed quite a few big clients.

Initially, Apollo Engineering is as Van den Akker puts it "between pub and church" located in a converted shop building. Ten years later, they moved to new premises on the outskirts of Aldeboarn. There they are still today, with roughly 30 employees, with Van den Akker and partner Erik Zwaagstra at the helm since 2010 after the founders stepped down. Apollo has all disciplines from sales to engineering and service in-house. The production of parts is outsourced off-site locally, but assembly is carried out in-house.

Remote IO system CPX-AP-I

With the decentralised IO system CPX-AP-I, I/O modules and decentralised valve terminals from Festo can be flexibly and scaleably connected to all common controllers (PLC systems) via, for example, EtherCAT, Profinet, Profibus and Ethernet/IP. Under a single bus node, you can link up to 79 devices, delivering significant savings. The different modules can be upto an impressive 50m apart - with IP65/IP67 classification - and all with real-time communication. Valve islands such as VTUG manifoldsare easy to integrate ensuring everything stays the same for the pneumatic control chain even if the PLC above changes. IO-Link masters can also be included within the AP technology. This allows real-time communication with smart components with IO-Link for commissioning and diagnostics, for example, with the OVEM vacuum generator used in this application. A plug-in for Festo Automation Suite is available and status data can be exchanged with cloud systems via Festo's IoT gateway CPX-IOT.