128
3 BASIC FUNCTION
3.15 Forced stop deceleration function
3.15
Forced stop deceleration function
Forced stop deceleration function is a function that decelerates the servo motor with commands when EM2 (Forced stop 2) is
turned off, and stops the servo motor with the dynamic brake when the servo motor rotates at the zero speed or less. This
enables the servo motor to stop with shorter coasting distance than stopping only with dynamic brake. When the forced stop
deceleration function is activated, [AL. 0E6 Servo forced stop warning] is shown in the display. The amount of time to reach 0
[r/min] or [mm/s] from the rated speed and the range of zero speed detection range can be set with the servo parameters.
[G] [WG]: The forced stop deceleration function can even be operated through commands from the network by using Quick
stop.
• In the torque mode and continuous operation to torque control mode, the forced stop deceleration function
cannot be used.
Precautions
• The forced stop deceleration does not operate on alarms that are not subject to the forced stop deceleration function.
• When the network communication is shut off, forced stop deceleration operates.
Page 127 When network communication shut-off or communication time-out has occurred [G] [WG]
• During normal operation, do not use EM2 (Forced stop 2) to alternate between stop and drive. Doing so may shorten the
service life of the servo amplifier.
• If an alarm that operates the dynamic brake occurs during forced stop deceleration, the braking distance until the servo
motor stops will be longer than the braking distance when the forced stop deceleration is properly operated.
• If STO is turned off during forced stop deceleration, the dynamic brake stops the servo motor, which may shorten the
service life of the dynamic brake relay.
• To prevent a malfunction in the dynamic brake or fire, do not drive the servo motor with an external force when the power is
shut off or an alarm or other factors trigger to activate the dynamic brake.
Setting method [G] [WG]
Set [Pr. PA04.3 Forced stop deceleration function selection] to enable/disable the forced stop deceleration function. Setting
[Pr. PA04.3 Forced stop deceleration function selection] to "2" (Forced stop deceleration function enabled) operates the
forced stop deceleration function when EM2 (Forced stop 2) is turned off. In addition, set the level of ZSP (Zero speed
detection) and the amount of time to reach 0 [r/min] or [mm/s] from the rated speed by using [Pr. PC07 Zero speed] and [Pr.
PC24 Deceleration time constant at forced stop].
Servo
parameter
Symbol
Name
Outline
PA04.3
*AOP1
Forced stop deceleration function
selection
Set "Forced stop deceleration function" to enabled/disabled.
0: Forced stop deceleration function disabled (EM1 is used)
2: Forced stop deceleration function enabled (EM2 is used) (initial value)
PC07
ZSP
Zero speed
Set the level of ZSP (Zero speed detection).
Initial value: 50 [r/min], [mm/s]
PC24
RSBR
Deceleration time constant at
forced stop
Set the deceleration time constant at forced stop.
Initial value: 100 [ms]