Page 12 - EngineerIt February 2021

AUTOMATION AND CONTROL

Rotary encoder with IO-Link –

the foundation for I4.0* applications

By Markus Egerer

ondition monitoring, predictive maintenance and cost pressure; preset function. If there are inaccuracies
this trend has been evident for years in the mechanical in a plant caused by slippage, the rotary
Cand plant engineering sector, the storage and encoder can adapt its position values
conveying technology sector, the renewable energy accordingly during operation. This
sector and others. The Pepperl+Fuchs absolute independent adaptation negates
rotary encoder with IO-Link communication the need for time-consuming
offers a suitable and long-term solution in this readjustment.
regard. With more than 11,4 million installed Furthermore, the
IO-Link network nodes and a growth rate of measured position values of
around 40 % compared to the previous year, the sensor have been
IO-Link has long established itself in the supplemented such that
field. It enables access to detailed evaluating potential machine
identification and diagnostic and states is supported. Such a
parameterisation data. machine state may be the
Product developers, plant engineering staff temperature, which is transmitted
and project managers are often faced with cyclically by the sensor through parameter
different objectives in a host of industry sectors. configuration so that continual measured
Customers expect short commissioning times, very high value checks can take place. This enables
machine availability and instant and rapid reaction times in the the temperature status of a plant to be
event of downtime. In addition, new savings potential in these areas must be continuously checked, since the rotary encoder
exploited to retain a competitive edge. Unexpected machine failures, in particular, often measures its external temperature and
result in losses amounting to six-digit figures. Against this backdrop, condition monitoring can thus display the plant temperature.
and predictive maintenance are the key words on everyone's lips. In the other absolute rotary encoder
These approaches harbour the motivation to make the maintenance and/or failure of product versions with IO-Link, this
machines more predictable. Upgrading the visualisation of the current technical machine parameter can be configured using the
status or the prediction of failure probability often requires a lot of work to make the measured values of rotational speed,
underlying data available. A data analysis can detect previously unknown correlations and acceleration, vibration and shock detection,
exclude false correlations with the help of sensor technology. The resulting interpretation of without the process data structure
the individual machine status is made available to plant operators or customers—usually via
downstream software services. Implementing a clear, structured, and error-free data basis is
essential, so that corresponding interpretations about the machine status are possible in the
first place. The Pepperl+Fuchs absolute rotary encoder with IO-Link communication already
offers solutions to this and can promise a high level of quality for cost-sensitive applications.

Simple data evaluation during operation
Two essential properties make the ENA**TL – IO-Link a technically suitable foundation for
condition monitoring systems.
In addition to a huge array of mechanical versions, Pepperl+Fuchs offers a variety of
configuration parameters. This means that all common application areas for absolute rotary
encoders can be realised with this product. The fact that the rotary encoder data is
transmitted at a transmission rate of 230,4 kBit/s (COM3) is particularly important for this
realisation. This is the fastest transmission speed in the IO-Link standard. The rotary
encoder offers a total resolution of up to 31 bits as well. Parameterisation of the multi-turn
information allows even cyclical applications to be optimally implemented. If, for example,
the same direction of rotation is always maintained in a plant because a sequence must
constantly restart from the beginning, the sensor can be configured so that the rotary
encoder starts counting with the position value "zero" again, once a certain position value
has been exceeded. This is called an overflow function. In addition, the sensor features a Markus Egerer

EngineerIT | February 2021 | 10