Efficient Networks Siemens Sinamics S120 - Manual (Page 208)

Basic functions
6.14 Position tracking
Drive Functions
208
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
The encoder position actual value in r0483 (must be requested via GnSTW.13) is limited to
2 32 places. When position tracking (p0411.0 = 0) is switched off, the encoder position actual
value r0483 comprises the following position information:
● Encoder pulses per revolution (p0408)
● Fine resolution per revolution (p0419)
● Number of resolvable revolutions of the rotary absolute encoder (p0421), this value is
fixed at "1" for singleturn encoders.
When position tracking (p0411.0 = 1) is activated, the encoder position actual value r0483 is
composed as follows:
● Encoder pulses per revolution (p0408)
● Fine resolution per revolution (p0419)
● Virtual number of resolvable motor revolutions of a rotary absolute encoder (p0412)
If the measuring gear is absent (n=1), the actual number of the stored revolutions of a
rotary absolute encoder p0421 is used. The position area can be extended by increasing
this value.
If the measuring gear is available, this value equals the number of resolvable motor
revolutions, which is stored in r0483.
● The gear ratio (p0433/p0432)
6.14.2 Measuring gear
6.14.2.1 Features
Measuring gear characteristics
● Configuration via p0411
● Virtual multiturn via p0412
● Tolerance window for monitoring the position at switching on p0413
● Input of the measuring gear via p0432 and p0433
● Display via r0483
6.14.2.2 Description
If a mechanical gearbox (measuring gearbox) is located between an endlessly rotating
motor/load and the encoder and position control is to be carried out using this absolute
encoder, an offset occurs (depending on the gearbox ratio) between the zero position of the
encoder and the motor/load whenever encoder overflow occurs.