Mitsubishi Electric MELSEC-L LD75P User Manual page 33

(a) Calculations of the movement amount per pulse, command pulse frequency, and the
deviation counter droop pulse amount
The movement amount per pulse, command pulse frequency, and the deviation counter droop pulse amount
are determined as follows:

Movement amount per pulse
The movement amount per pulse is determined by the worm gear lead, deceleration ratio, and the pulse
encoder resolution.
The movement amount, therefore, is given as follows: (Number of pulses output)  (Movement amount
per pulse).

Command pulse frequency
The command pulse frequency is determined by the speed of the moving part and movement amount
per pulse:

Deviation counter droop pulse amount
The deviation counter droop pulse amount is determined by the command pulse frequency and position
loop gain.
(b) Selection of unit for positioning is possible from mm, inch, degree, pulse
The LD75 allows the user to select from the following four units as the unit used by positioning commands to
any of the axes (1 to 4, if the module supports four axes): mm, inch, degree, and pulse. The unit selected for
one axis may differ from the unit selected for another axis.
When such data as the acceleration/deceleration time, positioning speed, and positioning address are correctly
set in consideration of the chosen unit, the LD75 can calculate the number of pulses required for a movement
amount to the target positioning address and execute the positioning by outputting a pulse train that includes
the calculated number of pulses.
L
A = [mm/pulse]
R × n
V
Vs = [pulse/s]
A
Vs
ε [pulse]
=
K
CHAPTER 1 PRODUCT OUTLINE
31
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