Description Of Operation - Mitsubishi Electric M800VW Series Programming Manual

M800V/M80V Series PLC Programming Manual (2/2)
14 PLC Help Function
14.31 Constant Torque Control

14.31.2 Description of Operation

Constant torque control
Constant torque control outputs a constant amount of torque in a single direction in accordance with the value configured by
"2296 SV096 (TQC) (Constant torque stopper control)". As axis movement is performed by servo drive to ensure a constant
servo motor torque, the position of the NC command is not changed and only the feedback position is updated. Therefore,
differences in command positions and feedback positions (hereinafter, referred to as position droop) occurs during constant
torque control. This position droop is cleared when the constant torque control is canceled once the axial movement via the
servo driver reaches the NC command position.
To clear the position droop without causing axial movement, you can use the constant torque control droop cancel function.
[Operation procedure]
(1) Confirm that the axis receiving constant torque control from the PLC has stopped (*1) and then set the constant torque
control request axis signal register (R2620/lower 8 bits) with the axis bits. (Multiple axes can be specified)
(2) As the PLC sets the constant torque control request axis signal, the servo motor for the specified axis outputs a constant
amount of torque in a single direction in accordance with the values configured to "2296 SV096 (TQC) (constant torque
stopper control)" for the specified axis.
(3) The NC outputs axis bits to the constant torque control request axis signal register (R624/lower 8 bits) at the PLC during
constant torque control.
(4) To cancel constant torque control, confirm that the PLC has stopped the axis (Note 1) and then turn OFF the axis bits for
the constant torque control request axis.
(5) The specified axis moves to the NC command position due to the PLC turning OFF the constant torque control request
axis signal.
(*1) To stop the axis, make sure that both the positive and negative signals (MVP and MVM: X7C0 through X7EF) are turned
OFF during movement of the specified axis.
[Operation sequence]
Feed axis selection
In axis minus motion*1
Constant torque control
request
Torque under constant
control
IB-1501668-B
R2620 Designated axis bit ON
R624 Controlled axis bit ON
784
Designated axis bit OFF
Controlled axis bit OFF