Torque Limit - Mitsubishi Electric MELSERVO-J4 MR-J4 A Series Instruction Manual

3. SIGNALS AND WIRING

(5) Torque limit

Cautions
(a) Torque limit and torque
By setting [Pr. PA11 Forward rotation torque limit] or [Pr. PA12 Reverse rotation torque limit], torque
is always limited to the maximum value during operation. A relation between the limit value and
servo motor torque is as follows.
A relation between the applied voltage of TLA (Analog torque limit) and the torque limit value of the
servo motor is as follows. Torque limit values will vary about 5% relative to the voltage depending on
products. At the voltage of less than 0.05 V, torque may vary as it may not be limited sufficiently.
Therefore, use this function at the voltage of 0.05 V or more.
(b) Torque limit value selection
The following shows how to select a torque limit using TL (External torque limit selection) from [Pr.
PA11 Forward torque limit] or [Pr. PA12 Reverse torque limit] and TLA (Analog torque limit).
When TL1 (Internal torque limit selection) is enabled with [Pr. PD03] to [Pr. PD22], you can select
[Pr. PC35 Internal torque limit 2].
However, if [Pr. PA11] and [Pr. PA12] value is less than the limit value selected by TL/TL1, [Pr.
PA11] and [Pr. PA12] value will be enabled.
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.
Maximum torque
CW direction
CW
100
Torque limit value [Pr.PA12]
in [Pr. PA12]
Maximum torque
0
0 0.05
TLA applied voltage [V] TLA
TLA applied voltage vs. torque limit value
TLA
Note. This diagram is for sink I/O interface. For source I/O interface, refer to section 3.9.3.
CCW direction
CCW
0 100
Torque limit value [Pr.PA11]
in [Pr. PA11]
±5%
2k
Japan resistor
RRS10 or equivalent
RRS10
[V]
3 - 33
[%]
Servo amplifier
TL
(Note)
( )
DOCOM
P15R
2k
TLA
LG
SD
Connection example