At Burkhardt+Weber (B+W), no-one needs to explain the benefits of the bi-directional communication interface IO-Link.

Based in Reutlingen in south-west Germany, this manufacturer of high-precision machining centres and even more of their customers have already learned to appreciate the many advantages when it comes to installation, configuration, diagnostics and service. In B+W’s new MCC series, the company has used Safety over IO-Link from Balluff to integrate safety into the overall concept of IO-Link. This makes the processes simpler, more efficient, cost-effective and of course safer.

Measuring 8 metres by 3 metres and 3.5 metres high, the MCC 630 exudes elegance and power, radiating a feeling of solid performance, precision and reliability within its compact dimensions. Not visible is the fact that this is a new series production machine with a complete set of possible uses. Nor is it obvious that behind the blue, grey and black facade of this machining centre is a modern control and safety concept from Balluff based on the digital IO-Link standard.

With Safety over IO-Link from Balluff, the system has the world’s first simple-to-install and easy-to-retrofit IO-Link safety system on-board. The advantage: both Balluff safety components as well as safety devices from other manufacturers can be easily connected to the newly developed Balluff safe I/O module using M12 standard cable. Even standard components such as binary sensors can be bundled via the new safety I/O module.

This also eliminates the need for a separate hub. Now the prerequisites for fully transparent configuration and diagnostics solutions, flexible and safe machine operation, as well as innovative Industry 4.0 concepts are provided.

Since 2012, B+W has been part of Indústrias Romi, the largest machine tool builder in Brazil. With around 250 employees, B+W is today an international manufacturer of machining centres for complex steel, cast and titanium parts of the highest quality. Notable among its customers are many key players in the aerospace and diesel motor industries, as well as in the machine tool sector. Whether as a standalone machine or part of an interlinked production system, the MCC 630 and MCC 800 series of flexible, fully digitised five-axis machining centres process workpieces efficiently and ready-to-install with just a few set-ups. In general it is the large motor or transmission parts that demand a number of various milling, drilling, turning and measurement cycles.

Balluff has been a technology provider and consultant to B+W for over 20 years.

“The co-operation over all the years has been outstanding, and we consider Balluff a reliable, creative and innovative partner,” says Benjamin Rother, Manager of Electronic Design at B+W.

Rother recounts when six years ago Nico Schmid, Sales Engineer at Balluff, first presented the intelligent IO-Link interface: “At that time we wanted to wait and see how this new standard would develop. But since 2014 we have been consistently and committedly using IO-Link in our machining centers.”

Until then B+W still used the traditional fieldbus-based wiring systems as the standard. Systematically separated from the standard signals, the safety-relevant signals were gathered in the field via ProfiNet. Cumbersome, complicated wiring was the order of the day, as were a variety of different cable types, sensors, actuators as well as tedious set-up procedures. Beyond the actual switching signal there was only little usable and processable information available from the process or sensor level.

When conceiving the new MCC series, the engineers at B+W pursued a clear objective. In addition to characteristic B+W features such as force, precision and availability, performance features were required that should benefit the manufacturer and operator equally: reducing the complexity in cabling; plug-in cables instead of discrete wiring; shortening the installation and commissioning phase; more transparency and information about what is happening in-place; and support through simple-to-use configuration, diagnostic and service concepts. Requirements that could be meet with amazing ease using the bi-directional communication interface IO-Link.

Codified in IEC 61131-9, this versatile point-to-point connection below the bus level has found broad acceptance among machine and systems builders. It clears the way for unhindered data exchange between the process location and the bus and control level, while providing a never-before-available amount of information to the user. Continuous monitoring, detection and visualisation of current machine states, individual warning levels, quality assurance and more can all be realised and documented with ease using IO-Link.

The new MCC machining centres are impressive power packs based on torsionally stiff cast components. With two independently operated plate changers, clamping a new workpiece is possible while the other one is being processed by a tilting spindle behind a safe chip protection door along five axes. The connected magazine holds more than 100 tools and can be easily expanded up to 320 slots.

The tools are automatically fed and are equipped with Balluff industrial RFID systems. Processing capacity up to 1.5 tons (or 2.5 tons for the MCC 800), axis drives with 17.5kN feed, and motor spindles with speeds up to 12,000rpm demonstrate that safety for man and machine is a central topic here. Each machining centre comes with multiple interlocks and light curtains – all drives, suspended loads such as the opened chip protection door, as well as the obligatory E-Stop buttons, are monitored.

“There was just no competition for Safety over IO-Link!” says Rother. “In interlinked production and assembly operations efficiency is especially important if high-performance systems are to have an optimal price-performance ratio. IO-Link offers us as the systems builder, and even more so our customers, a plethora of advantages. “

Safety over IO-Link from Balluff is the logical extension of the IO-Link philosophy and uses the advantages of IO-Link and PROFIsafe for safety-relevant signals as well. Like IO-Link, Safety over IO-Link also features simple system construction, time- and cost-saving wiring, minimal control cabinet space requirements and Lean system concepts. Safety always ends up on stop, as Safety over IO-Link applications can be adapted quickly and simply to changing requirements.

Every machining centre in the MCC series comes with a broad spectrum of Balluff products and systems: ten IO-Link sensor hubs with eight inputs and outputs each collect the signals from the distributed sensors and actuators, including numerous inductive and optical sensors from Balluff. The sensor hubs are configured as needed for the requirement – in other words, 16 signals can be freely assigned, all of which can be connected as is typical for IO-Link using standardised three-conductor cable with M12 connectors.

The sensor hubs channel to six installed ProfiNet IO-Link masters. Three Balluff safety hubs serve as safety gates. In addition to the industrial RFID systems, optional inductive couples from Balluff can be used: these transmit power and signals without contact over an air gap of up to 5mm. They are generally used where fixed wiring of sensors and actuators gets in the way, for example on rotary index tables and tool changers. As with the MCC series, when tools are placed in the machine, the controller does not release the gantry axes of the loading system until the clamping devices has reported perfect seating of the part to be processed via the opposite coupler modules.

Safety-relevant data is handled both safely and simply, as Safety over IO-Link uses elements of PROFIsafe. The IO-Link master itself remains a non-safety standard device and is considered a ‘black channel’: the transported data is tunneled through the master to the control level safely and untouched, and only there is it unpacked. The final programming is done using drag-and-drop from the programming interface of the controller.

Automation and safety technology in one results in more economical and more productive system concepts.

“The entire pallet of virtues that IO-Link brings with it, the simple integration of safety in the same system, provided the impetus for relying on the integrated Balluff Safety over IO-Link concept in the new MCC series,” Rother concludes. “We give our customers high-performance machining centres at an outstanding price-performance ratio that sets new standards when it comes to configuration, flexibility and service, and which are Industry 4.0 ready in every respect.”