Bosch Rexroth IndraDrive MPH-02 Functional Description page 555

Firmware for drive controllers

Table of Contents

MPH-02, MPB-02, MPD-02

Oscillating Signal Frequency

within one Output Cycle

Display Limits

Beat Effects in the Emulated

DOK-INDRV*-MP*-02VRS**-FK01-EN-P

Due to the internal signal processing, the periodic time and duty cycle of

the output signals are varying. The periodic time (or frequency) of the

resulting cycles can therefore be shorter or longer, too.

This is why the signals of incremental emulation should not be used for

measuring the speed by means of frequency measurement, but the

signals may only be evaluated by counting the increments.

Restrictions of Absolute Encoder Emulation

4096 revolutions in absolute form.

When using this kind of emulation at the display limits, small fluctuations

of the actual position lead to overflow and a position jump in the emulated

This is the case, for example, at position 0 and 4096 revolutions after

position zero.

position jump

S-0-0052, Reference distance 1

Display limits with absolute encoder emulation

This effect can be avoided by shifting the home point by executing

P-0-0012, C0300 Command Set absolute measuring.

By the respective setting in parameter S-0-0052, Reference

distance 1 shift the reference position to the middle of the

display range. This allows moving 2048 revolutions to the left

and to the right.

In case the position processing in the control unit and the position

detection (sampling) in the drive are not synchronized, beat effects can

occur in the emulated signal with a periodic time according to the formula

below, if the quartz frequencies on the drive and in the control unit cannot

be exactly (integrally) divided:

frequency deviation of the quartzes in control unit and drives

periodic time for the occurring beat frequency

Determining the periodic time

Extended Drive Functions

motor position in

Sv5089f1.fh7