Mitsubishi Electric MELSEC-L LD75P User Manual page 122

(4) [Pr.3] Movement amount per rotation (Al), [Pr.4] Unit magnification (Am)
The amount how the workpiece moves with one motor rotation is determined by the mechanical structure.
If the worm gear lead (mm/rev) is PB and the deceleration rate is 1/n, then
• Movement amount per rotation (Al) = PB  1/n
However, the maximum value that can be set for this "movement amount per rotation (Al)" parameter is
6553.5m (approx. 6.5mm). Set the "movement amount per rotation (Al)" as shown below so that the "movement
amount per rotation (Al)" does not exceed this maximum value.
• Movement amount per rotation (Al) = PB  1/n = Movement amount per rotation (Al)  Unit magnification
*1
(Am)
The unit magnification (Am) is a value of 1, 10, 100 or 1000. If the "PB  1/n" value exceeds 6553.5m, adjust with the
*1
unit magnification so that the "movement amount per rotation (Al)" does not exceed 6553.5m.
When movement amount per rotation (Al) = PB  1/n = 6000.0m (= 6mm)
Ex.
Movement amount per rotation (Al) = Movement amount per rotation (Al)  Unit magnification (Am) =
6000.0m  1 times
When movement amount per rotation (Al) = PB  1/n = 60000.0m (= 60mm)
Ex.
Movement amount per rotation (Al) = Movement amount per rotation (Al)  Unit magnification (Am) =
6000.0m  10 times
Programmable controller
CPU
module
Movement amount per pulse
PB 1
[mm/pulse]
Δ± = ×
Pf n
120
Servo amplifier
LD75
PB: Worm gear lead (mm/rev)
1/n: Deceleration ratio
Pf: Number of pulses from encoder (pulse/rev)
Servomotor
M G
Reduction gears
1
n
Encoder
Pf
Workpiece
PB