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SV200 DC Hardware Manual
920-0126A
4/14/2017
7.2.5 Electronic Gearing Ratio
The host command pulse count per revolution times the electronic gearing ratio set on the drive will result in the actual number of
pulses per revolution at the motor shaft. This feature allows more freedom and set up flexibility when a certain pulse count or moving
counter is required
If the step pulse per revolution is 10000 pulse/rev and the electronic gearing ratio is set to 1, when the host sends 10000 pulses, the
motor will turn 1 revolution. If the electronic gearing ratio is set to 1/2, then motor will move only 1 pulse position for every 2 pulses
the drive receives from the host, i.e. 20000 pulses for 1 motor revolution. In some cases, reasonable electronic gearing ratio can
simplify the calculation for the host when sending pulse commands.
Linear Actuator Example
Ball screw lead 3mm
Distance for screw lead move requirement is 4mm. (con’t. on next page)
If no electronic gearing is used, the following pulse count example shows the dilemma:
Because the screw lead is 3mm, (i.e. when the motor rotates 1 rev, the load moves 3mm), when a move distance of 4mm is required, it
is 4/3 of rev.
Pulse Count Requirement
If 1 motor rev requires 10000 pulses, then
= 13333.33333
…
pulses
This leads to infinitely repeating number with a cumulative error in pulse counter.
If using an electronic gearing ratio:
If 1 pulse is set to 1um, and 10000 pulse per rev, the Electronic gearing ratio can be set as follows:
If Electronic gearing ratio is set to
, then 1 pulse send by the host, will leads to 1um movment at the load.
Parameter Settings
Parameter
Name
Data Range
Default
LED
Display
P-39 (EG)
Required pulse per rev
200~51200
10000
5000
Set Required pulse per rev
P-40 (PV)
Secondary Required
pulse per rev
200~51200
20000
10000
Set secondary Required pulse per rev
P-41 (EN)
Electronic gearing
Ratio Numerator
1~1000
1000
1000
Set Electronic gearing Ratio Numerator
P-42 (EU)
Electronic gearing
Ratio Denominator
1~1000
1000
1000
Set Electronic gearing Ratio
Denominator
