The "IO-Link" system is now also opening up the final level of control engineering by means of communication technology: sensors and actuators that previously only transmitted signals and switching states to the programmable logic controller (PLC) are now making available their entire intelligence and functionality system-wide.
The question now becomes how to utilize this extra information as effectively as possible in order to achieve productivity increases during the configuration, commissioning and system operation.
Regarding parameterization capability, diagnostics and data storage, a philosophy for the field device connection is now making its arrival with IO-Link, which has proven itself for many years in higher-level system structures such as the field bus technology with PROFIBUS DP and PROFINET IO. Although it stands to reason that with the increasing information scope from the industrial field area, the complexity of the system configuration and thus the project expenses will grow. The acceptance of a new IO-Link system on the market, however, rises and falls with the weighing of the system's benefits against the effort involved.
This difficulty is ideally solved by the Totally Integrated Automation (TIA) from Siemens, where " as the basis for customized automation solutions " integrated data storage and the operation of all native devices within a software platform ensure that a consistent system is safely constructed without multiple entries of parameters. But since automation tasks often have to be executed with heterogeneous hardware/network structures, the complexity of connecting the components from different manufacturers represents an important factor in determining the acceptance of a new standard such as IO-Link, which is being supported by many manufacturers.
Figure 1: By integrating the parameterization of Siemens sensors and actuators into the programming environment Step7, their intelligence and functionality can now be utilized system-wide via IO-Link; previously, only signals and switching states were transmitted to the programmable logic controller (PLC).
The pioneers in the field bus area relied on a far-reaching support of software standards that were defined by the PROFIBUS user organization: if an interconnection of components from different manufacturers is required here, the device manufacturer provides a suitable software module enabling the implementation of this device in the engineering environment of the PROFIBUS/PROFINET master. But how does this implementation take shape in the case of IO-Link?
IO-Link: Becoming a standard through manufacturer-independence
IO-Link as well wants to supply considerable additional information to the automation system. In doing so, this additional information naturally describes the functionalities of sensors and actuators. For logical reasons, they are mapped exactly at the place, where the user also finds the parameterization of the other communication paths: in the configuration tool of the engineering system. Since the hardware structures and parameters of the entire automation system " from the process control down to the field bus nodes " have already been configured there, the sensor and actuator parameterization has to take place there as well.