Articles Archive > Profibus and IO-Link - strong as team

Profibus and IO-Link - strong as team

Comau Inc., a worldwide leading supplier of manufacturing solutions, has developed a new manufacturing cell, the “Smart Cell”, with fast automatic tool change. Comau trusts thereby in whole on IO-Link and the use of inductive couplers for the wireless transmission of power and signals. The sensor technology specialist and Networking supplier Balluff supplied the components.

All the mounting steps interruption-freely performed

Two alternating operating robot arms and a pallet positioning system are positioning the workpieces.

March 25 2010 This system is used as well by a well-known motor manufacturer for fully automatic cylinder head mounting. It performs interruption-freely all the mounting steps of a manufacturing cell even in mixing mode.


Heart of the system are a Cartesian robot with two alternating operating arms and a pallet positioning system for the spatial positioning of the workpieces in the three space axes. While one robot arm is still being busy with the mounting of the workpiece, the second is already preparing the next mounting step by changing the grabber.

High demands on the interface of change tools

The inductive couplers BIC substitute solid cable connections.

High demands are made on the interface of the change tools because they carry apart from much pneumatics still as far as 16 sensors and a RFID tag. A parallel wiring of the sensors was not desired for reasons of the expenses and above all the reliability. Therefore the technical designers with Comau faced the challenge to connect the tool that can be changed automatically with Profibus.

Mechanical interface?

Originally it was intended to cope with this challenge by implementing a mechanical interface such as spring loaded contact pins or an autocentering plug connector. Apart from doubts regarding the reliability of electrical contacts and abrasion resistance of this solution there was however still another further striking argument that favoured an alternative solution with IO-Link.


The time to restart after a tool change was in the range of several seconds with Profibus, definitely not matching the required cycle times.

IO-Link brings the solution

Simplifying drastically the installation of the machine by the inductive couplers on IO-Link.

IO-Link establishes at one fell swoop several smart simplifications of the interface to the tool.


So-called IO-Link hubs bundle up to 16 binary sensors on IO-Link using just three cores as is well-known. On its own this would already drastically simplify a mechanical transfer interface.


However, the engineers with Comau continued still a further step substituting the mechanical interface by inductive couplers contactlessly transferring the IO-Link across a distance of 5 mm.


So suddenly all problems regarding reliability of electrical contacts and wear are released in a lasting and elegant manner. Furthermore the availability of IO-Link ports at the master simplifies the connection of the RFID read head. There it can be connected via its IO-link interface as simply as a usual binary sensor.

IO-Link improves cycle times and system availability

Albert Feinäugle, Manager Marketing Services, Balluff GmbH

Perhaps the most important benefit however is the restart after a tool change. The IO-Link connection is again ready within less than one second improving cycle times and system availability in a decisive manner.


To email Albert Feinäugle, click here


Finding out all around IO-Link from Balluff, click here.



Zum Seitenanfang