
3. START-UP PROCEDURE START-UP PROCEDURE B-65235EN/02
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6) Set CMR with the scale of a distance the NC
instructs the machine to move.
CMR = Command unit / Detection unit
CMR 1/2 to 48 Setting value = CMR × 2
Usually, CMR = 1, so specify 2.
7) Specify the flexible feed gear (F.FG). This
function makes it easy to specify a detection unit
for the leads and gear reduction ratios or various
ball screws by changing the number of position
feedback pulses from the pulse coder or separate
detector.
Setting for the α or β pulse coder in the semi-closed mode
(Example of setting)
For detection in 10 µm unit, specify as follows:
Ball screw lead
Number of necessary
position pulses
F.FG
10(mm/rev) 1000(pulse/rev) 1/1000
20 2000 2/1000 or 1/500
30 3000 3/1000
(Example of setting)
If the machine is set to detect in 100 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. 100 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 × 100 = 3600 pulse
=
F.FG numerator (≤ 32767)
1000000
F.FG denominator (≤ 32767)
Number of position
necessary for each
revolution of the motor
(as
irreducible
fraction)
NOTE 1
For both F.FG numerator and denominator, the maximum
setting value (after reduced) is 32767.
=
F.FG numerator
1000000
F.FG denominator
3600
=
10000
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