5 Operation
68 SD780 Series Servo Technical Manual
Steps
Content
Mechanical system
Ball screw
Rotary table
Belt + Pulley
1
Machine
specification
Ball screw lead: 6mm
Reduction ratio: 1/1
Rotation angel per turn:
360°
Reduction ratio: 1/100
Pulley dia: 100mm
(Pulley circumference
314mm)
Reduction ratio: 1/50
2
Encoder
resolution
8388608 (23 bit)
16777216 (24 bit)
131072 (17 bit)
83886708 (23 bit)
16777216 (24 bit)
131072 (17 bit)
8388608 (23 bit)
16777216 (24 bit)
131072 (17 bit)
3
Command
unit
0.001mm (1mm)
0.01°
0.005mm (5mm)
4
Load shaft
movement in
1 rotation
(command
unit)
6mm/0.001mm = 6000
360° /0.01° = 36000 314mm/0.005mm = 62800
5
Electronic
gear ratio
𝐵
𝐴
=
83388608
6000
×
1
1
𝐵
𝐴
=
83388608
36000
×
100
1
𝐵
𝐴
=
83388608
62800
×
50
1
6
Parameters
Pn204: 8388608
Pn204: 838860800
Pn204: 419430400
Pn206: 6000
Pn206: 36000
Pn206: 62800
5.2.3 Deviation Clearance
The deviation clear signal (/CLR) is the input signal to clear the servo unit deviation counter.
1.
Clear signal wiring
Deviation clear signal wiring can be divided into linear driver output and open collector output.
Please refer to “Position Command Input Circuit” for wiring details.
Cautions
！
1. Electronics gear ratio numerator (Pn204) set to 0, electronic gear ratio than the denominator (Pn206) set
the value of the number of pulses corresponding to the motor running one lap, for example, Pn204
(numerator) set to 0, Pn206 (Denominator) set to 10000, it means that the upper computer (PLC, motion
controller, etc.) send 10000 pulses servo motor turn one lap.
2. 0.001 ≤ electronic gear ratio (B/A) ≤ 83887 beyond this setting range, "Parameter Setting abnormality
(Er.040) alarm" (for 23 bit encoder).
24 bit encoder
Ball screw lead: 6mm
Command unit: 0.001mm
Load shaft
Reduction
ratio1:100
Load shaft
Command unit: 0.01°
24 bit encoder
Reduction
ratio 1:50
Pulley dia: 100mm
Load shaft
Command unit: 0.005mm
24 bit encoder
