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Technical Description
68
ATM60 / ATM90 / KHK53
Dec 2021
11 Technical Description
11.1 Description of the Rotary Encoders
The absolute rotary encoders ATM 60-P/ATM 90-P have a total resolution of 26 bits. The single-
turn position value is transmitted with 13 bits (8192 steps/rev.). The number of revolutions in the
multi-turn range also is 13 bits (8192 rev.). The revolutions are determined via a gearbox
mechanism.
The Profibus DP interface is an integral part of the encoder. The encoder is configured as a
slave, with cyclical data transmission mode (DP-V0).
The encoder functionality is implemented by the profile for encoders.
11.2 Description of the Linear Encoder
The KHK53-P is a real absolute length measuring system with a resolution of 100 µm and sup-
ports a measuring length of up to 1700 m.
A – non-contact – reading head determines the absolute position from a series of scale sections
(material measures) fitted along the measurement path.
The reading head itself consists of a number of magnetoresistive sensors, which can always
evaluate the position of at least three permanent magnets (fitted inside the material measure
elements) to always determine – from their coded relative distances – the absolute position.
The material measure elements are made from an aluminium sections. These are mounted at
fixed intervals – in a row, using a mounting aid, until the required measuring length is achieved.
The reading head moves parallel along the material measure elements.
The distance between the reading head and a material measure is nominally 25 mm .
The Profibus DP interface is an integral part of the encoder. The encoder is configured as a
slave, with cyclical data transmission mode (DP-V0).
The encoder functionality is implemented by the profile for encoders.
11.3 Profibus Interface – Brief Overview of Specific Features
•
Profibus DP according to EN 50 170-2 (RS485), implemented with ASIC SPC3 by Siemens.
•
Electrical isolation of the bus interface.
•
Functionality according to 'encoder profile' (profile for encoders).
•
Configuration using hardware settings (DIP switches) in the bus connection adapter hous-
ing:
Electronic pushbutton adjustment (PRESET)
Address setting (NODE ID)
Counting direction (cw, ccw)
•
Status information of the message link via LED (red).
•
Configurable parameters of the encoder via the protocol:
Profile-specific parameters:
Counting direction, scaling function, scaling parameters (CPR, CMR).
Manufacturer-specific settings:
Enabling the SSA Service, selecting the address setting (switch or protocol), extended
I/O data transmission (speed, time stamp).
Storage of all important data parameters in the EEPROM.
•
Formation of new position values at
intervals of 0.250 ms
.