4 APPLICABLE FUNCTIONS
4.11 Speed limit [G] [WG]
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4.11
Speed limit [G] [WG]
During the torque mode, this function serves to limit the servo motor speed in order not to generate excessive speed.
• Speed limit can be used only in the torque mode.
• When [Velocity limit value (Obj. 2D20h)] is mapped to cyclic communication, values written from
engineering tools are overwritten from the controller.
Precautions
• When the servo motor speed reaches the speed limit value, torque control may become unstable.
Setting method
Set the maximum speed to [Pr. PT67 Speed limit]. The speed limit direction and torque command direction are the same
direction. There is no speed limit in the torque command direction and the opposite direction. [Pr. PT67] is used for [Velocity
limit value (Obj. 2D20h)].
If [Pr. PT01.1 Speed/acceleration/deceleration unit selection] is set to "1" (command unit/s), set the maximum speed in [Pr.
PV21 Speed limit extension setting].
*1 Available on servo amplifiers with firmware version A5 or later.
Checking "Limiting speed" status
When the servo motor speed reaches the speed set in [Pr. PT67 Speed limit], VLC (Limiting speed) and Bit 4 (S_VLC) of
[Status DO2 (Obj. 2D12h)] will turn on.
Servo
parameter
Symbol
Name
Outline
PT67
VLMT
Speed limit
Set the maximum speed for the torque mode.
Initial value: 3000.00 [r/min], [mm/s]
Servo
parameter
Symbol
Name
Outline
PV21
VLMTE
Speed limit extension setting
Set the maximum speed for the torque mode.
Initial value: 2147483647 [command unit/s]