6.3 Electronic Gear
120
6.3
Electronic Gear
The electronic gear function enables the servomotor travel distance per input reference pulse from
host controller to be set to any value. One reference pulse from the host controller is the minimum unit
and is called as one reference unit.
The electronic gear function allows the host controller generating pulses to be used for control without
having to consider the machine deceleration ratio or the number of encoder pulses.
6.3.1 Setting the Electronic Gear
Calculate the electronic gear ratio (B/A) using the following procedure, and set the values in parame-
ters Pn20E and Pn210.
1. Check the machine specifications.
Items related to the electronic gear:
• Deceleration ratio
• Ball screw pitch
• Pulley diameter, etc.
2. Check the number of encoder pulses for the servomotor.
Servomotor Model
Number of Encoder Pulses (pulses/rev.)
SJME
8192
When the Electronic Gear is Not Used
When the Electronic Gear is Used
Ball screw pitch: 6 mm
Workpiece
No. of encoder pulses: 81
9
2
Reference unit: 1 mm
:
To move a workpiece 10 mm:
1 revolution is 6 mm. Therefore,
10 / 6 = 1.6666 revolutions
81
9
2 pulses is 1 revolution. Therefore,
1.6666
×
81
9
2 = 13653 pulses
13653 pulses are input as references.
The equation must be calculated at the
host controller.
To move a workpiece 10 mm using reference units:
The reference unit is 1mm. Therefore,
to move the workpiece 10 mm (10000 mm),
1 pulse = 1 mm, so
10000/1 = 10000 pulses.
Input 10000 pulses.
Ball screw pitch: 6 mm
No. of encoder pulses: 81
9
2
Workpiece
Ball screw pitch
Deceleration ratio
TOEP_C710806_03A_1_0.book Seite 120 Montag, 2. Juli 2007 3:55 15
