Technical data

16-18 Notes Application MHD Sychronous motors
DOK-MOTOR*-MHD********-PR05-EN-P
16.8 Motor encoder
To control the motor speed and/or to position the motor, the drive
controller requires information on the current motor position.
To achieve this, the integrated encoder unit makes the appropriate
signals available to the drive controller. The drive controllers are capable
of transmitting the positional value thus determined to a superordinate
CNC or SPS.
The encoder electronics is equipped with a data memory where the motor
type name, the control loop parameters and the motor parameters are
filed.
These data are read by the digital intelligent drive controllers by Bosch
Rexroth. This ensures
• quick and easy startup,
• adjustment between the motor and the drive controller without the risk
of damage to the motor.
MHD motors are available with the two following types of position
detectors:
• Relative position detector
• Absolute position detector
Technical data of motor encoder
Description Digital servo feedback (HSF) Digital servo feedback (HSF) with
integrated multiturn absolute encoder
Measurement method Optically
Position resolution at the motor 512 x 2
13
= 4.194.304 bits of information / revolution
System accuracy
± 0.5 angular minutes
Type of position detector Relative Absolute (more than 4096 motor
revolutions)
Fig. 16-24: Technical data of motor encoder
Provided for relative indirect position detection. Replaces separate
incremental encoders at the motor.
Note: After a voltage failure or after the first POWER ON, the axis
must first always be moved to its home position.
Provided for absolute indirect position detection within 4096 motor
revolutions. Replaces separate absolute value encoders at the motor.
With this encoder version, the absolute position of the axis is preserved
even after voltage switchoff.
Digital servo feedback (HSF)
Digital servo feedback (HSF)
with integrated multiturn
absolute encoder