Technical data

7 Accessories and Options
7.1 Motor Encoder
7.1.1 General
To control the motor speed and/or to position the motor, the drive controller
requires information on the current rotor position.
To achieve this, the integrated encoder unit makes the appropriate signals
available to the drive controller. The drive control devices can transfer the po-
sition value determined in this manner to a superordinate controller.
The encoder electronics are equipped with a data memory where the motor
type name, the control loop parameters and the motor parameters are filed.
Rexroth drive control devices read out these data. This ensures
● quick and easy startup,
● adaptation between the motor and the drive controller without the risk of
damage to the motor.
7.1.2 Motor Encoder Technical Data
Option Encoder type Measuring
method
System accuracy Position recording type Position resolution on
the motor
S1
Singleturn Hiper-
face optical en-
coder
Optically ± 80 angular seconds
Absolute (more than 1 mo-
tor revolutions)
128 x 2
13
= 1,048,576
bits of information / rev-
olution
M1
Multiturn absolute
optical encoder
Absolute (more than 4096
motor revolutions)
S2
Optical encoder
singleturn EnDat
2.1
Optically ± 20 angular seconds
Absolute (more than 1 mo-
tor revolutions)
2048 x 2
13
= 16,777,216
bits of information / rev-
olution
M2
Optical encoder
multiturn absolute
EnDat 2.1
Absolute (more than 4096
motor revolutions)
Fig.7-1: Motor Encoder Technical Data
These encoders permit absolute, indirect position recording within one me-
chanical rotation. The encoders replace a separate incremental encoder on the
motor.
After a power failure or after the first POWER ON, the axis must first
always be moved to its home position.
Exception: Applications in which the maximum working path is with-
in one mechanical rotation of the motor.
These encoders permit absolute, indirect position recording within 4096 me-
chanical rotations. The encoders replace a separate absolute value encoder
on the motor. With this encoder version, the absolute position of the axis is
preserved even after voltage switch-off.
Singleturn optical encoder Option
S1, S2
Multiturn absolute optical encoder
Option M1, M2
Project Planning Manual | Rexroth IndraDyn S Electric Drives
and Controls
| Bosch Rexroth AG 125/194
Accessories and Options