Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - MECHATROLINK-II Communications Reference - Manual (Page 111)

4 Operation
4.4.3 Electronic Gear
4-26
Encoder Resolution
Encoder resolution can be checked with servomotor model designation.
(2) Electronic Gear Ratio Setting Examples
The following examples show electronic gear ratio settings for different load configurations.
Electronic gear ratio setting range: 0.001 ≤ Electronic gear ratio (B/A) ≤ 4000
If the electronic gear ratio is outside this range, a parameter setting error 1 (A.040) will
be output.
SGM V  
Symbol Specification Encoder Resolutions
Symbol Specification Encoder Resolutions
3 20-bit absolute 1048576
D 20-bit incremental 1048576
A 13-bit incremental 8192
SGMPS  
2 17-bit absolute 131072
C 17-bit incremental 131072
SGMCS غغغغغغغ
Symbol Specification Encoder Resolutions
3 20-bit absolute 1048576
D 20-bit incremental 1048576
Rotation
Step Operation
Load Configuration
Ball Screw Disc Table Belt and Pulley
1
Check machine specifica-
tions. Ball screw pitch: 6 mm
Gear ratio: 1/1
Rotation angle per revolu-
tion: 360
°
Gear ratio: 1/100
Pulley diameter: 100 mm
(pulley circumference: 314
mm)
• Gear ratio: 1/50
2
Check the encoder reso-
lution.
1048576 (20-bit) 1048576 (20-bit) 1048576 (20-bit)
3
Determine the reference
unit used. Reference unit: 0.001 mm
(1
μm)
Reference unit: 0.01 °
Reference unit: 0.005 mm
(5
μm)
4
Calculate the travel dis-
tance per load shaft revo-
lution. (Reference unit)
6 mm/0.001 mm=6000 360 °/0.01°=36000 314 mm/0.005 mm=62800
5
Calculate the electronic
gear ratio.
6 Set parameters.
Pn20E: 1048576 Pn20E: 104857600 Pn20E: 52428800
Pn210: 6000 Pn210: 36000 Pn210: 62800
Ball screw
pitch: 6 mm 20-bit encoder
Load shaft
Reference unit: 0.001 mm
20-bit encoder
Load shaft
Reference unit: 0.01 °
Gear ratio:
1/100
Load shaft
Gear ratio
1/50
Reference unit: 0.005 mm
Pulley diameter:
100 mm
20-bit encoder
1048576
6000
1
1
= ˜
B
A B
A 1048576
36000
100
1
= ˜
B
A 1048576
62800
50
1
= ˜