Mechanical Axis System And Measuring Systems; Measuring Systems For Motor And Axis Control, Arrangement - Bosch Rexroth IndraDrive MPH-02 Functional Description

5-70
Motor, Mechanical Axis System, Measuring Systems
Setting the Initial Position Value
In the Case of Distance-Coded
Measuring System
5.5

Mechanical Axis System and Measuring Systems

Measuring Systems for Motor and Axis Control, Arrangement

Motor Encoder
External Encoders
Notes on Commissioning
The commissioning guidelines in the sections "Basics on
Measuring Systems, Resolution" and "Monitoring the Measuring Systems"
have to be observed, too!
If the actual position value of relative encoders is not to be written with the
default value "0" when the drive is switched on, P-0-0019, Initial position
value has to be changed to have the desired value.
If the relative encoder possesses distance-coded reference marks the
controller is informed on this by the respective bit in the following
parameters:
• S-0-0277, Position feedback 1 type
• S-0-0115, Position feedback 2 type
The value for the "shorter distance" of the distance-coded reference
marks has to be entered in the S-0-0165, Distance-coded reference
offset A parameter.
The value for the "longer distance" of the distance-coded reference marks
has to be entered in the S-0-0166, Distance-coded reference offset B
parameter.
Brief Description
Controlled motor activation requires a position measuring system that
measures the current rotor position or the position of the moving part as
opposed to the static part of the motor.
This position measurement is required for the:
• current control loop,
• velocity control loop and, if required,
• position control loop.
The precision and resolution of the position measurement is decisive for
the quality of the actual values, especially in the velocity and position
control loop.
Depending on the mechanical properties of the mechanical system
between driven motor shaft and machine axis it can be required to carry
out the position control by means of an external position encoder (not
integrated in the motor) directly at the moving part of the axis, e.g. in the
case of
• mechanical system with slip,
• gear play or a low degree of stiffness of the mechanical system, etc.
The external (optional) encoder can also be used as a measuring wheel
encoder (frictionally engaged on transported material).
See "Measuring Wheel Mode" in chapter "Drive Functions"
MPH-02, MPB-02, MPD-02
DOK-INDRV*-MP*-02VRS**-FK01-EN-P