Torque Limit Function - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

7.3

Torque Limit Function

This function restricts the generating torque of the servomotor within the setting range.
If the torque required for control exceeds the torque limit value during positioning control, it restricts with the setting torque
limit value.
Default of the torque limit value
The default 300.0[%] is set as torque limit value at the servo amplifier's control circuit power supply or Multiple CPU system's
power supply ON.
Even while the Multiple CPU system power supply is ON, the torque limit value is returned to the default value
of 300.0[%] when the control circuit power supply of the servo amplifier is turned ON again, or when the
SSCNET communication is disconnected or connected again. Set the torque control value again as required
using the Motion SFC program or the Motion dedicated PLC instruction.
Setting method of torque limit value
Set the torque limit value by the following method.
The positive direction of torque limit value restricts the forward rotation (CCW) driving and reverse rotation (CW) regenerative
torque of servo motor, and the negative direction of torque limit value restricts the reverse rotation (CW) driving and forward
rotation (CCW) regenerative torque.
Setting method
Parameter block
Servo program
Motion SFC Torque limit value
program change request (CHGT)
Motion dedicated Torque limit value
PLC instruction change request
instruction (M(P).CHGT/
D(P).CHGT) .
*1 MELSEC iQ-R Motion Controller Programming Manual (Program Design)
Priority of torque limit value setting
When the multiple torque limit values are set on the same axis, the latest torque limit value is valid. However, the setting of
torque limit value set in the parameter block or servo program is valid only if lower than the torque limit value set in the Motion
SFC program or Motion dedicated PLC instruction.
When the torque limit value is set individually for positive direction and negative direction in the Motion SFC
program or Motion dedicated PLC instruction, only either one of the positive direction or negative direction
may become valid depending on the setting value of servo program.
7 AUXILIARY AND APPLIED FUNCTIONS
428
7.3 Torque Limit Function
Setting details
Set the torque limit value in the parameter block. By setting the
parameter block No. used in the servo program, the torque limit
value of specified axis is changed to same value for both of
positive direction and negative direction for every positioning
control.
Set the torque limit value in the parameter block. By setting the
parameter block in the home position return data and JOG
operation data for every axis, the torque limit value at home
position return and JOG operation is changed to same value for
both of positive direction and negative direction.
By setting the torque limit value in the servo program, the torque
limit value of specified axis at servo program execution is changed
to same value for both of positive direction and negative direction.
Executing the torque limit value change request (CHGT) in the
operating control step of Motion SFC program changes the torque
limit value of specified axis. A different value for positive direction
and negative direction can be specified.
Executing the torque limit value change request instruction
(M(P).CHGT/D(P).CHGT) in the PLC CPU changes the torque
limit value of specified axis. A different value for positive direction
and negative direction can be specified.
Setting Setting Reference
range units
1 to 10000 0.1[%] Page
215
Parameter
Block
Page
242
Positioning
Data
*1