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Sigma II User's Manual
5.2.5
Using the Electronic Gear Function
The electronic gear function enables the servomotor travel distance per input refer-
ence pulse to be set to any value. It allows the pulses generated by the host control-
ler to be used for control without having to consider the equipment gear ratio or the
number of encoder pulses.
When the Electronic Gear
Function is Not Used
No. of encoder pulses: 2048
To move a workpiece 0.39in. (10mm):
1 revolution = 6mm. Therefore,
10 ÷ 6 = 1.6667 revolutions.
(2048 × 4) pulses = 1 revolution. So,
(1.6667 × 2048 × 4) = 13653 pulses
13563 pulses are input as the reference.
The equation must be calculated at the
host controller.
n
Setting the Electronic Gear
Calculate the electronic gear ratio (B/A) using the following procedure, and set the
values in parameters Pn202 and 203.
1. Check equipment specifications related to the electronic gear:
•
Deceleration ratio
•
Ball screw pitch
•
Pulley diameter
2. Check the number of encoder pulses for the SGMoH servomotor.
Servomotor Model
and Encoder
Specifications
A
B
C
Workpiece
Ball screw pitch: 0.24in. (6mm)
Ball screw pitch
Deceleration ratio
Encoder Type
Incremental encoder
1
Absolute encoder
2
Chapter 5: Parameter Settings and Functions
When the Electronic Gear
Function is Used
No. of encoder pulses: 2048
To move a workpiece 0.39in. (10mm):
Equipment conditions and reference
units must be defined for the electronic
gear function beforehand.
Reference unit is 1µm. Therefore,
10mm
1µm
Number of Encoder Pulses
Per Revolution (p/rev)
13–bit
16–bit
17–bit
16–bit
17–bit
5-28
Workpiece
Reference unit: 1µm
Ball screw pitch: 0.24in. (6mm)
=
10000 pulses
2048
16384
32768
16384
32768
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