Chapter 8. How to Use Position Servo
8-8
8.6.1 Inputting position command pulse
3 types of command pulses, ① A phase + B phase, ② CW pulse + CCW pulse and ③
direction + pulse, can be selected. Input applicable number to [Pulse Logic (P4-14)].
Command pulse operation is effected based on the encoder pulse value multiplied by 4.
Menu Menu name Unit Display range Initial value Mode
P4-14 Pulse Logic 0 ~ 5 1 P
8.6.2 Electronic gear
The electronic gear enables setting of motor feed per input command pulse in a random
value. The electronic gear is multiplied by the number of the command pulses to
electronically play the role of a gear. FDA 5000 series are capable of inputting 4 different
electronic gear ratios, and the selection of the electronic gear is decided by the input
contacts (GEAR1) and (GEAR2).
Gear 1 Gear 2 Menu Menu name Unit Display range Initial value Mode
P4-06 ELCTR Gear1 NUM 1 ~ 99999 1 P
OFF OFF
P4-07 ELCTR Gear1 DEN 1 ~ 99999 1 P
P4-08 ELCTR Gear2 NUM 1 ~ 99999 1 P
ON OFF
P4-09 ELCTR Gear2 DEN 1 ~ 99999 2 P
P4-10 ELCTR Gear3 NUM 1 ~ 99999 1 P
OFF ON
P4-11 ELCTR Gear3 DEN 1 ~ 99999 3 P
P4-12 ELCTR Gear4 NUM 1 ~ 99999 1 P
ON ON
P4-13 ELCTR Gear4 DEN 1 ~ 99999 4 P
[Setting Electronic Gear]
1) Determine the minimum unit (command unit) of the position data which feeds load per
pulse.
Assumed command unit = 0.001 [mm]/ pulse.
2) Obtain the load feed rate per load axis rotation in the unit of command.
Example) In case the ball screw pitch is 5[mm], and command unit is 0.001 [mm]/pulse.
Load feed per load axis rotation = 5/0.001 = 5000
3) Get electronic gear ratio in case of reduction ratio (n/m).
Number of motor encoder pulse x 4
Electronic gear ratio =
Feed per load axis rotation
X
(motor axis speed) Electronic gear ratio (numerator)
reduction ratio
(load axis speed)
=
Electronic gear ratio
(denominator)
4) The results of calculating the electronic gear ratio must be between 0.05-20.