Information About Encoders; Basics; The Resolution And The Output Frequency Of The Encoder - Leibinger RAPID Series Technical Information

Information about encoders

6 Information about encoders
Regarding the encoders that are used for a high-speed application, there are two limitations to be
considered. The first one is the maximum output frequency of the encoder and the other one is
the maximum input frequency of the X1 encoder input interface of the printer.

6.1 Basics

Regarding speed measuring the RAPID printers work with internal speed as well as with an
external encoder.
An external encoder has the advantage that a varying production speed would not affect the
quality of the print out. Additionally the printer would recognize a stop of the production line.
Nevertheless, using an encoder for high-speed printing requires a careful selection of the
encoder.

6.2 The resolution and the output frequency of the encoder

The resolution of an encoder indicates the number of pulses per rotation.
An encoder, for instance, with a resolution of 2.500 indicates that the encoder provides 2.500
pulses per rotation of the encoder axis.
Normally there is a measuring wheel with a circumference mounted on the axis of the encoder.
The given circumference of the measuring wheel and the resolution of the encoder results in the
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pulses per mm.
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2.500 ������������ ���� ��������
If, for instance, the circumference of the measuring wheel is 200 mm the resolution is:
= 12,5 ������������ ���� ��������/��������
200 ��������
In order to determine the output frequency of the encoder, which represents also the input
frequency at the X1 encoder interface of the printer, the resolution has to be multiplied with the
actual production speed.
If, for instance, the production speed is 1000 m/min  1.000.000 mm/min the input frequency
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is:
Important:
It is highly recommended thoroughly checking the technical specifications of the encoder that is
used. An encoder with a high resolution leads to high output frequencies at high-speed
operations.
Make sure that the encoder is able to manage such frequencies!
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∗ =
12,5 ������������ ���� �������� 1.000.000 ��������
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Output
frequency
of the
encoder
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∗
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= 208.333,33
12.500.000 ������������ ���� ��������
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Input
=
frequency
of the
printer
= 208,33 ������������
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