Siemens SINAMICS V90 Operating Instructions Manual page 176

Control functions
7.3 Pulse train input position control (PTI)
Calculation formula for electronic gear ratio
The electronic gear ratio can be calculated from the formula below:
Examples for calculating the electronic gear ratio
Step Description
1 Identify mechanism
2 Identify encoder resolu-
tion
3 Define LU
4 Calculate the travel
distance per load shaft
revolution
5 Calculate electronic
gear ratio
6 Set param- p29012/p
eters 29013
176
Ball screw
Pitch of ball screw: 6 mm
•
Deduction gear ratio: 1:1
•
10000
1 LU=1 μm
6/0.001=6000 LU
(1/6000) × (1/1) × 10000 = 10000/6000
= 10000/6000 = 5/3
Mechanism
Disc table
Rotary angle: 360
•
Deduction gear ratio: 3:1
•
10000
1 LU=0.01
o
360 /0.01 =36000 LU
o o
(1/36000) × (3/1) × 10000 = 10000/12000
= 10000/12000 = 5/6
SINAMICS V90, SIMOTICS S-1FL6
Operating Instructions, 09/2015, A5E36037884
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