BECKHOFF DK9222-0711-0051 - Manual (Page 6)

XFC
XFC technology microincrements
Application Note DK9222-0711-0051
Practical example | Virtual maximization of the physical encoder resolution through
microincrements
The semi-edge inaccuracy of the encoder is eliminated by using the microincrement mode of the Beckhoff EP5101 EtherCAT
Box with encoder interface. In this mode, the EtherCAT Box automatically interpolates the position scans to be transferred
over a width of 8 bits. Therefore, this mode offers a 256 times higher resolution than the encoder is able to provide physically.
The microincrement mode is only suitable for motion analyses, because for interpolation within the EtherCAT Box, the position
is sampled with a significantly higher resolution than is passed on to the fieldbus in interpolated form. The principle of
interpolation in the EtherCAT Box requires a minimum speed, i.e. microincrements cannot be analyzed at (or near) standstill.
Submitted
values
per cycle
Encodersignal
Submitted
values
by using
microincrements
4 5 6 7 3
3.05 4.6 5.8 6.5 7.48
Fig.  Different encoder signals resolutions (with and without microincrements)
The EP5101 EtherCAT Box is an interface for the direct connection of incremental encoders with differential inputs (RS485).
Due to the optional interpolating microincrement function, the EP5101 can supply even more precise axis positions for dynamic
axes. In addition, it supports the synchronous reading of the encoder value together with other input data in the EtherCAT
system via high-precision EtherCAT distributed clocks (DC). The encoder is connected via an 8-pin M12 socket (EP5101-0002)
or via a 15-pin D-sub socket (EP5101-0011).
New Automation Technology Beckhoff 6
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