16. DIGITAL SERVO
823
Series/edition When driven by α
servo amplifier
When driven by αi
servo amplifier
9096 series A D
90B0 series A N
(3) Arbitrary AMR function
PRM
#7
#6 #5 #4 #3 #2 #1 #0
2001
AMR7 AMR6 AMR5 AMR4 AMR4 AMR3 AMR2 AMR1
NOTE Set “00000000”.
(4) CMR
1820
Command multiply ratio
PRM
1) When CMR is 1/2 to 1/27
2) When CMR is 0.5 to 48
(5) N/M of feed gear (F⋅FG)
2084
n for flexible feed gear
PRM
2085
m for flexible feed gear
PRM
Setting for the αi pulse coder in the semi–closed mode
Necessary position feedback pulses
per motor revolution
(Note 1)
F⋅FG numerator (v 32767)
(as irreducible fraction)
1,000,000 (Note 2)F⋅FG denominator (v 32767)
=
NOTE1 For both F⋅FG number and denominator, the maximum setting val-
ue (after reduced) is 32767.
NOTE2 αi pulse coders assume one million pulses per motor revolution, ir-
respective of resolution, for the flexible feed gear setting.
NOTE3 If the calculation of the number of pulses required per motor revolu-
tion involves π, such as when a rack and pinion are used, assume
π to be approximately 355/113.
[Example]
For detection in 1 µm units, specify as follows:
Ball screw lead
(mm/rev)
Number of neces-
sary 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
Set value=
1
CMR
+100
Set value=2×CMR