SD710 Series Servo User Manual Chapter 9 Parameter description
44
Factory value: 1
Setting range: 0 to 1073741824
Unit: N/A
Control mode.
□
P
Parameter
Description
Used to set the numerator value of the electronic gear ratio.
Caution
● When this function code is set to 0, the drive automatically sets the electronic gear
numerator
internally with the resolution of the encoder.
For example
.
When the serial encoder resolution is 17 bits and set to 0, the drive sets itself internally to N = 131072.
When the serial encoder resolution is 24 bits and set to 0, the drive internally sets itself N = 16777216.
When the serial encoder resolution is 23 bits and set to 0, the drive internally sets itself to N=8388608.
Pn206
Electronic gear denominator (M)
○
Communication
address: 0x0206
★
Factory value: 1
Setting range: 1 to 1073741824
Unit: NA
Control mode
.
□
P
Parameter
Description
The e-gear function is to provide easy change of travel ratio. Usually a large e-gear ratio will cause a
step change in the position command, which can be improved by smoothing it out with an S-curve or
low-pass filter. For example, when the electronic gear ratio is equal to 1, the motor encoder enters at
10,000 ppr per week, and when the electronic gear ratio is equal to 0.5, every two pulses on the
command side corresponds to one pulse wave of motor rotation.
The servo motor is prone to surge when set incorrectly, so the user should set the electronic gear ratio
reasonably.
The reduction ratio of the motor shaft and load side of the machine is
A
B
(load rotates A while motor
rotates B) the electronic gear ratio can be set by the following equation.
●
Electronic gear ratio
N
M
=
𝐸𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑖𝑐 𝑔𝑒𝑎𝑟 𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒
𝐸𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑖𝑐 𝑔𝑒𝑎𝑟 𝑑𝑒𝑛𝑜𝑚𝑖𝑛𝑎𝑡𝑜𝑟
=
Pn204
Pn206
=
𝑀𝑜𝑡𝑜𝑟 𝐸𝑛𝑐𝑜𝑑𝑒𝑟 𝑅𝑒𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
One revolution of load shaft movement (command unit)
×
B
A
For
example, the
servo motor encoder resolution is 10000p/rev, the ball screw lead is 6mm, and the
workpiece moves 10mm when the command is input to the upper computer to output the number of
pulses.
No electronic gear ratio used
Because the servo motor rotates one week when the screw moves 6mm, when moving 10mm, the
servo motor needs to rotate 10 ÷ 6 = 1.6666 turns, then it needs 1.6666 × 2500 × 4 = 16666 pulses,
and the command is input to the upper computer to output 16666 pulses.
！