Siemens SINAMICS S120 Getting Started page 162

Performing basic parameterization
6.3 Drive axes
10 mm distance are travelled per load revolution. According to the encoder resolution,
maximum 15,000 LU/10 mm = 1,500 LU per mm can be defined. We will select 1,000 LU per
mm (1 LU = 1 µm). 10 mm per revolution results in 10,000 per revolution:
● p2506 = 10,000 LU per load revolution
Example 2: Rotary axis (encoder on the motor side)
Gear ratio i = 44.5
● p2504 = 445 motor revolutions
● p2505 = 10 load revolutions
Target variable to be controlled: °
Encoder resolution = 364,544 LU
360° are travelled per load revolution. According to the encoder resolution, maximum
364,544 LU/360° = 1012 LU per ° can be defined. We will select 100 LU per ° (1 LU = 0.01°).
360° per revolution results in 36,000 LU per load revolution.
● p2506 = 36,000 LU per load revolution
Example 3: Modulo axis – chain drive
The chain has 250 chain links and a chain link is 0.0338667344 m long. The output wheel
has 40 teeth, i.e. 40 chain links are moved per revolution. The target positions are at a
distance of 25 chain links to one another.
Gear ratio i = 114.28 (rounded off)
Ratio of the number of teeth of the gearbox = 106,967/936
● p2504 = 106,967 motor revolutions
● p2505 = 936 load revolutions
Encoder resolution = 468,095 LU
The encoder resolution is too low here to convert the chain links to a linear SI unit without
rounding-off errors having an effect on the modulo correction. A chain link must therefore be
taken as target variable.
Target variable to be controlled: 1 chain link
40 chain links travelled per load revolution. According to the encoder resolution, maximum
468,095 LU/40 chain links = 11,702 LU per chain link can be selected. We will therefore
select 1,000 LU per chain link (1 LU = 33.8667344 µm). 40 chain links per revolution results
in:
● p2506 = 40,000 LU per load revolution
● p2576 = 250,000 LU modulo range
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Getting Started, 12/2018, 6SL3097-5AG30-0BP0