User manual of EL8-EC***F AC Servo
268
2.
Set direction of external encoder
Please make sure the direction of the external encoder is the same as the motor encoder
to prevent motor runaway.
a) Enter position JOG mode. Jog the motor in the same direction at low velocity. Monitor
if the feedback value of d21 absolute encoder single turn position and d21_1 external
encoder are changing in the same trend. If they are not the same, inverse the setting
of Pr0.32.
b) The feedback value of d21 and d21_1 can be verified by pushing the axis and
monitoring the trend of the changes. Please make sure the servo axis is disabled.
c) Use trial run to set up a reciprocating motion. Max velocity > 200rpm. If d49 = 1 after
several cycles of motion, set Pr0.32 to 1; d48 External encoder feedback pulse count
per revolution.
3.
Set external encoder feedback pulse count
When Pr0.37 = 0, set external encoder feedback pulse count per revolution in Pr0.36. If
the lead size of lead screw and encoder accuracy are known, please calculate using the
formula below and enter the result into Pr0.36.
Pr0.36 =
Lead size of lead screw (mm)
Encoder accuracy ( μm
pulse)
23-bit encoder resolution = 8388608 pulses
Please make sure the parameters are set correctly to avoid excessive position deviation
especially after long range motion. This may trigger excessive hybrid control deviation
error alarm.
Parameter
Label
Range
Description
Pr0.35
External encoder
frequency divider
numerator
0~2
23
To set external encoder frequency divider
numerator
When Pr0.35 = 0, numerator = resolution of
encoder
Pr0.36
External encoder
frequency divider
denominator
1~2
23
To set external encoder frequency divider
denominator
Pr0.37
External encoder
feedback pulse count
per revolution
0~2147483648
When Pr0.37 = 0, Pr0.36 set value = external
encoder feedback pulse count per revolution.
Parameter
Label
Range
Description
Pr0.31
External
encoder type
0~3
=0
：
ABZ incremental encoder
=1
：
Communication incremental encoder
=2
：
Communication absolute incremental
encoder (Tamagawa protocol)
=3
：
BISS-C
