
4. SERVO FUNCTION DETAILS B-65150E/04
− 262 −
4.17.8 Position Feedback Switching Function
When the full preload function is enabled, low servo rigidity can result
in vibration, as shown in Fig. 4.17.8 (a), only in the case of driving by
the sub-axis. In such a case, stable operation can be achieved by using
the position feedback switching function.
01 2 3 4
−
10
0
−80
−60
−
40
−
20
0
20
sec
Motor speed (− command)
01 2 3 4
−20
0
20
40
60
80
100
sec
Motor speed (+ command)
Drive by the main motor Drive by the sub-motor
Fig. 4.17.8 (a) Motor speeds with plus-direction and minus-direction commands
#7 #6 #5 #4 #3 #2 #1 #0
1952
−
PFBSWC
2008
−
PFBSWC (#6) 1: Switches position feedback according to the direction of a torque
command.
0: Always uses main axis position feedback.
(Set this parameter for the main axis only.)
(Series 9060/P(16) and subsequent editions)
(Series 9080/A(01) and subsequent editions)
(Series 9090/C(03) and subsequent editions)
(Series 90A0/A(01) and subsequent editions)
CAUTION
Always set this bit while the system is in the
emergency stop state. After rewriting this bit, always
turn the power to the NC off, then back on.