Signal Management and Wiring: the IO-Link Is the Solution

The Vicenza-based company Essebi Automation has designed and built a machine capable of assembling every 13 seconds a connector for fragrance diffuser or insect repellent for the US market.
Thanks to the collaboration with Balluff and the use of an IO-Link module, it has been possible to solve the issues regarding the management and communication of the signals coming from the machine, thus considerably simplifying wiring on the main rotary table, the actual heart of the line.

by Fabrizio Dalle Nogare

No frills, concreteness, clear mind. And the wish to test and try innovative solutions. Just a few words are enough to understand the qualities that have allowed Essebi Automation to remain, for over 10 years, in the process automation market, designing and manufacturing machines that are currently working all over the world.
Giovanni Bisognin opens the doors of its company in Brendola, in the province of Vicenza. Together with his brother Stefano, he manages a company of about 20 people: mechanical and electrical designers, assembly operators and programmers. Essebi Automation’s primary specialization lies in the field of software, although in the year following its foundation in 2008, the company began to build its own machines, given the pressing demand coming from customers.
These are, needless to say, special automation machines, in most cases robotic cells with six-axis or SCARA robots. In addition to assembly (rotary table lines, pallets or fast handling machines), the applications made over the years range from the machine tools or moulding presses tending – in the plastics sector in particular – to machines for handling pharmaceutical components.

Monitoring and traceability not only in automotive
We ask Mr Bisognin if, in time of Industry 4.0 and digitized production, the fact of being a software specialist is an important advantage for the company. “Of course, it can be an advantage – he replies – but it is essential not to lose pace with the technologies that are emerging, especially in recent years. The advent of Industry 4.0 has allowed us to focus our attention on elements such as the human-machine interfaces or the communication of the machine itself with the customers’ networks. We see that the needs for monitoring and traceability are becoming more popular also because end users show such a requirement more and more, not only in the automotive industry. Today, even in the case of simpler products, there is a need to provide full traceability of the production cycle. The latest technologies indeed make this possible”.
Speaking of trends that characterize the sector, it is quite important to mention the issue of flexibility, a requirement – coming more and more often from customers during the discussion of the order – which should however be balanced with the cycle time, and therefore with the machine overall throughput. “It is not easy to highlight a general trend, as it depends heavily on the single application – adds Giovanni Bisognin -. Certainly, customers today invest more and more in solutions that allow him to produce not a single product, but a range of parts or variations that might be manufactured in the future. The greater flexibility, however, must not affect the cycle time, to be established of couse in the bidding phase. In short, we try to work on both levels, cycle time and flexibility, at the same time”.

Three rotary tables to assemble a connector
A word, flexibility, also mentioned about the machine that Essebi Automation has developed for an important customer. This machine – made of three rotary tables, one of which has a much higher level of complexity than the others – designed for assembling a connector for fragrance diffuser or insect repellent. While the machine, which ensures the creation of a moulded, assembled and finished connector every 13 seconds, is already at work in China, the product is designed for the US market.
“The project – says Mr Bisognin – featured quite a relevant issue in terms of network technology and wiring. In fact, it was necessary to implement 128-bit communication with only 4 wires available, as it also had to manage components such as solenoid valves and sensors. For this reason, we felt that the best solution was Balluff Automation’s IO-Link master, to be integrated with the various slaves. This allowed us to monitor and control all the secondary stations”.

From sensors to the IO-Link master
The collaboration between Essebi Automation and Balluff began a few years ago, in 2015, by using the sensors of the German company. The relationship, also based on the commercial and technical support provided by Balluff and on the wide range of solutions proposed, has evolved and become more solid with the use of the IO-Link solutions, the standard thought to allow the reliable and flexible exchange of information from production machines that, after a first inevitable launch phase, is spreading among machine manufacturers.
“The ability to monitor the individual sensors more efficiently, but also the guarantee of a certain flexibility, were the factors that led us initially to try this technology”, says the owner of Essebi Automation. “The wiring is also leaner and faster, offering higher control over the single elements. The IO-Link is a technology that allows us to connect several products of different types (pneumatic components, for example) and then process all the data in a single solution. We are using it more and more on our machines to facilitate monitoring and data exchange. In addition – adds Giovanni Bisognin – it is possible in a few steps to integrate this technology even on existing machines”.

From part assembly to control
Talking about on to the work cycle of the assembly machine, the starting point is the single resistor, selected by means of a special system and placed on the first rotary table. By means of a welding operation, the resistor is joined to the body of the connector which, once complete, is inserted on a plastic base by means of an ultrasonic welding operation. An electrical testing station was set up to check the conductivity before unloading, with a system for the recognition of waste.
The machine provides two types of control: a visual one, by means of a machine vision system, and an electric one, in fact, to be sure that the product meets certain parameters, of course set by the customer.
“The main rotary table, made of eight stations and managed by an electro-pneumatic rotary joint, has been made using only six cables thanks to connection solutions such as the IO-Link standard and the Profinet communication protocol”, explains Mr Bisognin. “The solution also allowed us to adapt to the speed of the rotary table without waiting for the signal to arrive via other protocols”.
Following the customer’s requirements, the machine is prepared for a rapid format changeover, functional to the production of different product variants: the fragrance diffuser and the insect repellent have indeed different features also in terms of size. The format changeover takes place by changing some mechanical components, such as the placements, or rather by working on the human-machine interfaces and the software.

The video shows the assembly machine for connectors in action.
Fabio Rosso (Balluff) talks about features and potential of the IO-Link standard.