6encoder evaluation – Lenze 9400 User Manual
Page 248
6
Encoder evaluation
6.3
Parameter setting
248
Lenze · Servo-Inverter 9400 HighLine · Reference manual · DMS 10.0 EN · 11/2013 · TD05/06
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6.3.4
Position feedback with a linear distance measuring device
This function extension is available from software version V4.0!
Linear distance measuring devices (e.g. with Hiperface
®
or EnDat interface) are only used for
additional position feedback in the case of servo-controlled drives. For speed and current control, a
motor encoder is always necessary.
For applications with low requirements regarding dynamic response and speed accuracy, the use of
sensorless V/F control (VFCplus) and position feedback for position control is possible.
6.3.4.1
Conversion from linear to rotative encoder variables
Like the signals of rotative position encoders, the signals of linear distance measuring devices are
read in at encoder input X8. The actual position value of these usually optical encoders is thus
directly available for position control. Additional block interconnection is not necessary.
Evaluation at encoder input X8 is designed for rotary encoders. In order to adapt the linear system,
conversion to (notional) rotative values, which have to be entered in the code, is necessary.
Conversion for the number of encoder increments in
In the case of linear distance measurement devices, the encoder resolution is usually indicated in
the form of graduations in [μm] or as a number of increments per millimetre [inc/mm].
The following rule of thumb can be used to determined the number of encoder increments
[6-4]
Determination of the number of encoder increments of linear distance measuring devices
The integer value (INT = integer part of the calculation) must be entered in
rounding-off error is corrected by means of the position encoder gearbox factor (
in the machine parameters.
See
Determination of the position encoder gearbox factor of linear distance measuring devices
The resulting maximum position which can be shown can be checked in
.
The maximum speed that can be shown is indicated in
If the necessary speeds and positions for the application can no longer be shown,
enlarged. The internal resolution is thus decreased.
Number of encoder increments
Feed constant [units/rev]
Encoder graduation [units]
---------------------------------------------------------------------
=
C00420 = INT number of encoder increments
C02524
Encoder graduation
---------------------------------------------------
=