
B-65270EN/05 4.SERVO FUNCTION DETAILS
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<2> Direction of motor rotation
1879 (FS15i)
Direction of motor rotation (DIRCT)
2022 (FS30i, 16i)
Main axis: With a forward direction specified, 111 specifies that the
main axis motor rotates counterclockwise as viewed from
the motor shaft side, while -111 specifies the opposite
direction.
Sub-axis: To cause the sub-axis motor to rotate in the same
direction as for the main axis, specify the same value for
both the sub-axis and the main axis because of their
mechanical structure. To cause the sub-axis motor to
reverse, specify a value whose sign is opposite to that for
the normal direction. For winding tandem, be sure to
specify the values with the same sign.
<3> Position feedback setting
Specify position feedback for both main axis and sub-axis. (See
Subsec. 4.18.8 for a concrete example.)
* Assume position feedback shown in Fig. 4.18.8 (a) not only for
the main axis but also for the sub-axis.
Series 30i,16i, Series 15i
and so on
• Semi-closed or full-closed loop setting No. 1815#1 No. 1815#1
No. 1807#1
• CMR setting No. 1820 No. 1820
• Setting the reference counter capacity No. 1821 No. 1896
• Setting the high-resolution Pulsecoder No. 2000#0 No. 1804#0
• Setting the number of velocity detection pulses
No. 2023 No. 1876
• Setting the number of position detection pulses
No. 2024 No. 1891
• Flexible feed gear (numerator) setting No. 2084 No. 1977
• Flexible feed gear (denominator) setting No. 2085 No. 1978
(4) Descriptions of servo parameters for adjustment
The load inertia ratio to be specified for axes subjected to tandem
control differs from that for ordinary axes.
1875 (FS15i)
Load inertia ratio (LDINT)
2021 (FS30i, 16i)
[Standard setting] (Load inertia/motor inertia) × 256
(NOTE) In typical tandem control, the total load inertia of the machine is borne
by two motors. So, calculate the load inertia for the above formula as
follows:
(Load inertia) = (Total load inertia of machine)/2
When the full preload function is used, the motor on the driving side
is required to bear the total load inertia of the machine and the motor
inertia of the other motor. So, calculate the load inertia for the above
formula as follows:
(Load inertia) = (Total load inertia of machine) + (Motor inertia)