Introduction
Kendrion Kuhnke Automation GmbH
14
17 May 2021
3 Introduction
3.1 EtherCAT®
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— Ethernet Control Automation Technology
EtherCAT is the most powerful Ethernet-based fieldbus system currently available on the market.
EtherCAT puts up the top speed mark, and its flexible topology and simple configuration make it the
perfect means of controlling extremely fast processes. To give you a clue: 1000 I/Os can be
addressed in 30 μs.
Because of its high performance, the simple wiring and its open protocol support, EtherCAT is often
used as a fast motion control and I/O bus driven by an industrial PC or in conjunction with control
technology on a smaller scale. EtherCAT moves beyond the limits of conventional fieldbus systems.
Its interconnections between the controller at one end and both the I/O modules and drives at the
other are as fast as those of a backplane bus. EtherCAT controllers thus nearly act like centralised
control systems, overcoming the issue of bus transfer times that conventional fieldbus systems are
burdened with.
3.2 Kuhnke FIO (Fast Input / Output)
Kuhnke FIO is a system of modules interconnecting via the backplane bus to make up a so-called
EtherCAT network able to transfer process signals. For example, a Kuhnke FIO system may comprise
a Kuhnke FIO controller or bus coupler plus any number of Kuhnke FIO I/O modules.
The head module (controller or bus coupler) converts the physical transfer technology (twisted pair) to
LVDS (E-bus) and generates the system voltages required by the LVDS modules. The standard 100
Base Tx lines used for office network communications connect to the one side, the Kuhnke FIO I/O
modules for the process signals connect to the other. This is how the Ethernet EtherCAT protocol is
retained right through to the last I/O module. At the end of the modular device, the connection
between the forward and return lines is automatically closed, the effect being that another 100 Base
Tx line can be plugged in to connect the next EtherCAT unit to the second bus coupler port.
If the bus coupler is the last EtherCAT network station, i.e. if its RJ45 "Out" socket remains unplugged,
the connection between the forward and return lines is automatically closed.
Kuhnke FIO Controller 113 and several Kuhnke FIO I/O modules
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EtherCAT® is a registered trademark and patented technology, licenced by Beckhoff Automation
GmbH, Germany.
