33
(denominator) low bit*1
once
P0-95
Group 2 Electronic gear ratio
(denominator) high bit*10000
0
-
1
～
65535
Servo bb
At
once
Note:
(1) P0-11~P0-14 is all about the parameters of electronic gear ratio, P0-11, P0-12 is group 1, P0-13, P0-14 is
group 2, but the priority of P0-11 and P0-12 is higher than that of P0-13 and P0-14. Only when P0-11 and P0-12
are set to 0, the ratio of electronic gear P0-13 and P0-14 will take effect.
(2) When P0-11, P0-12, P0-13 and P0-14 are all set to 0, P0-92, P0-93, P0-94 and P0-95 will take effect.
2. Calculation of Pulse Number per Rotation and Electronic Gear Ratio
Steps
Content
Description
1
Confirm
the
machine
specification
Confirm the deceleration ratio n:m(servo motor turns m
rotations while load turns n rotations), ball screw distance,
pulley diameter.
2
Confirm the encoder pulse
Confirm the servo motor encoder accuracy
3
Set the command unit
Determine the actual distance or angle corresponding to 1
pulse of the controller
4
Calculate the command pulses
the load shaft rotates 1 circle
Based on the determined command unit, calculate the
command quantity n of the load shaft rotating for 1
revolution.
5
Calculate the pulses per rotation
M
Command pulse number of motor shaft rotating for 1 turn
M=N/(m/n).
6
Set the pulses per rotation
(P0-11/P0-12) or
Electronic
gear
ratio
(P0-13/P0-14)/(P0-92~95)
P0-11=M%10000
P0-12=M/10000
priority
n
N
m
M
14
0
P
13
0
P
=
=
−
−
resolution
encoder
resolution
encoder
Note:
(1) In step 6, the effective priority of the number of pulses per revolution is higher than the electronic gear ratio,
that is, when P0-11 ~ P0-12 are all 0, P0-13 ~ P0-14 will take effect. In special cases, if the number of pulses per
revolution is calculated as a decimal, the electronic gear ratio should be considered.
(2) When P0-13 and P0-14 exceed the setting range, please divide the electronic gear ratio into numerator and
denominator. If the ratio still exceeds the parameter setting range, please use the second gear ratio P0-92~P0-95.
Only when P0-11~14 = 0, the second gear ratio takes effect.
(3) The resolution of DS5 series servo motor encoder is 131072 (17 bits) and 8388608 (23 bits).
(4) The command unit does not represent the machining accuracy. On the basis of the mechanical accuracy,
refining the instruction unit quantity can improve the positioning accuracy of the servo system. For example,
when using the lead screw, the mechanical accuracy can reach 0.01mm, so the unit equivalent of 0.01mm is more
accurate than the unit equivalent of 0.1mm.
3. Example of setting the electronic gear ratio
steps
Name
Ball screw
Round table
Belt + pulley
1
Confirm
mechanical
specifications
Ball screw pitch: 6mm
Machine deceleration ratio: 1:1
1-circle rotate angle: 360°
Deceleration ratio: 1:3
Pulley diameter: 100mm
Deceleration ratio: 1:2
2
Confirm
the
number
of
encoder
Encoder resolution 131072
Encoder resolution 131072 Encoder resolution 131072
Load shaft
D: pulley diameter
1rotate =
command unit
πD
Load
shaft
command unit
1 rotate =
360 °
P: pitch
P
1rotate =
command unit
P
Load shaft
