5 Operation
100 SD780 Series Servo Technical Manual
𝐵
𝐴
=
𝑃𝑛204
𝑃𝑛206
=
1 instruction unit movement (Command unit)× number of segments of linear encoder
Pitch of grating ruler for linear encoder
=
Movement corresponded with input command 1 pulse
Movement corresponded with grating ruler output 1 pulse
Supplementary Notes
About resolution
The resolution used in the servo unit (the movement of 1 feedback pulse) can be obtained as
following formula:
Resolution (the movement of 1 feedback pulse) =
the grating ruler pitch of linear encoder
the segment number of serial conversion unit or linear encoder
The servo unit controls the servo motor in the unit of feedback pulse.
5.8.8 Setting example of electronic gear ratio
The grating ruler pitch of linear encoder = 1 cycle distance of analog voltage feedback signal sent
by linear encoder.
The lead of screw rod is 16mm and the transmission ratio is 1:1 (direct connection).
Semi closed-loop mode:
Steps
Contents
Mechanical composition
1
Number of motor encoder lines
24bit encoder lines number 16777216
2
The number of pulses required
for one turn of the screw rod
The command unit is 0.0005mm (0.5 μm),
and the number of pulses is 32000
3
Electronic gear ratio
𝐵
𝐴
=
16777216
32000
4
Parameter
Pn204=16777216, Pn206=32000