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3. SIGNALS AND WIRING
(3) Ready (RD)
Servo-on (SON)
ON
OFF
Yes
No
Alarm
ON
OFF
Ready (RD)
100ms or less 10ms or less
10ms or less
(4) Torque limit
CAUTION
If the torque limit is canceled during servo lock, the servo motor may suddenly
rotate according to position deviation in respect to the command position.
(a) Torque limit and torque
By setting parameter No. PA11 (forward torque limit) or parameter No. PA12 (reverse torque limit),
torque is always limited to the maximum value during operation. A relationship between the limit value
and servo motor torque is shown below.
Torque limit value in
parameter No. PA11
Max. torque
T
o
rq
u
e
0
100
Torque limit value in
parameter No. PA12
100
[%]
Forward rotation (CCW) direction
Reverse rotation (CW) direction
(b) Torque limit value selection
As shown below, the internal torque limit selection (TL1) can be used for selecting the torque limit
between the forward torque limit (parameter No. PA11) or the reverse torque limit (parameter No. PA12)
and the internal torque limit 2 (parameter No. PC14).
However, if the value of parameter No. PA11 or parameter No. PA12 is lower than the limit value
selected by TL1, the value of parameter No. PA11 or parameter No. PA12 is made valid.
(Note) Input
device
Limit value status
Validated torque limit values
TL1
Forward rotation (CCW)
driving
Reverse rotation (CW)
regeneration
Reverse rotation (CW)
driving
Forward rotation (CCW)
regeneration
0
Parameter No. PA11
Parameter No. PA12
1
Parameter No. PC14
Parameter No. PA11
Parameter No. PA12
Parameter No. PA11
Parameter No. PA12
Parameter No. PC14
Parameter No. PA11
Parameter No. PA12
Parameter No. PC14
Parameter No. PC14
Note. 0: off
1: on
(c) Limiting torque (TLC)
TLC turns on when the servo motor torque reaches the torque limited by the forward torque limit, the
reverse torque limit or the internal torque limit 2.