
6. DIGITAL SERVO
B–64115EN/01
380
[Example]
For detection in 1 µm units, specify as follows:
Ball screw lead
(mm/rev)
Number of necessary
position pulses
(pulses/rev)
F⋅FG
10
20
30
10000
20000
30000
1/100
2/100 or 1/50
3/100
[Example]
If the machine is set to detection in 1,000 degree units with a gear
reduction ratio of 10:1 for the rotation axis, the table rotates by 360/10
degrees each time the motor makes one turn.
1000 position pulses are necessary for the table to rotate through one
degree.
The number of position pulses necessary for the motor to make one turn
is:
360/10 1000 = 36000 with reference counter = 36000
Setting for use of a separate detector (full–closed)
Number of position pulses corresponding
to a predetermined amount of travelF⋅FG numerator (v 32767)
(as irreducible fraction
Number of position pulses corresponding
to a predetermined amount of travel from
a separate detector
F⋅FG denominator (v 32767)
=
[Example]
To detect a distance of 1–µm using a 0.5–µm scale, set the following:
<<Examples of calculation>>
1/1000 mm 1/10000 mm
One revolution 8mm
of motor 10mm
12mm
n=1/m=125
n=1/m=100
n=3/m=250
n=2/m=25
n=1/m=10
n=3/m=25
(7)Direction of travel
2022 Rotational direction of motor
PRM
111 : Normal (clockwise) –111 : Reverse (counterclockwise)
F⋅FG numerator
F⋅FG denominator
=
36000
1,000,000
=
36
1000
Numerator of F⋅FG
Denominator of F⋅FG
=
L/1
L/0.5
=
1
2