Electronic Gear Ratio - Leadshine EL8-EC Series User Manual

4.2 Electronic gear ratio

When loaded axis moved for 1 command unit, it corresponds to motor encoder unit which
is converted in more comprehensible physical units such as μm. The use of electronic
gear ratio is to turn the movement in physical units to required pulse count equivalency.
Electronic gear ratio =
Rotor might be connected to load through reducer or other mechanical structures. Hence,
the gear ratio is closely related to reducer gear ratio, position encoder resolution and
mechanical dimensions related parameters.
Electronic gear ratio =
Electronic gear can be set through Pr0.08. If Pr0.08 ≠ 0, Pr0.08 is valid. If Pr0.08 = 0,
object dictionary 6092-01 is valid.
Command pulse count per motor revolution needs to be
Revolution / 8000.
EL8-EC series comes with motors with 23-bit encoder. Pulse count per revolution for
23-bit encoder = 8388608. From the condition above, the command pulse count per motor
revolution for 23-bit encoder ≥ 1049.
Name
Pr0.08
Range
Activation
Pulses per revolution can be set using object dictionary 608F, 6091, 6092. However, Pr0.08 has
higher priority.
Name Encoder resolution
Index
608Fh-0
R
Access
1 0
To set encoder resolution
Electronic gear ratio
Index Name
numerator
6091h-0
1 Access RW
To set electronic gear ratio numerator
Electronic gear ratio
Index Name
Rotor movement (Encoder unit)
Loaded axis movement(Command unit)
Encoder resolution
Loaded axis resolution
Command pulse counts
per revolution
0~838860 Uni
P-
8 t
After restart
Unit
Mappin
TPDO Mode
g
Mapping RPDO Mode
User manual of EL8-EC***F AC Servo
≥
Encoder Pulse Count per
Mode
Default 0
Encoder unit Structure VAR
F
Range
Structur
r
Unit
e
F Range
r
Unit Structur
F
Index 2008h
Type UInt 32
1~214
74836 0
Default
47
Dint
VAR
Type
32
1-21474
Defaul
1
83647 t
VAR Dint
Type
157