Forced Stop Deceleration Function; Setting Method [G] [B] - Mitsubishi Electric MELSERVO-J5 User Manual

3.17

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 zero speed detection range can be set with the servo parameters.
[G]: The forced stop deceleration function can even be operated through commands from the network by using Quick stop.
Page 195 Quick stop [G]
[B]: The forced stop deceleration function can even be operated through the emergency stop command from the controller.
For details, refer to each controller manual.
• In the torque mode and continuous operation to torque control mode, the forced stop deceleration function
cannot be used.
• When connecting multiple MR-J5D_-_G_ to one MR-CV, set [Pr. PC46.2 Protection coordination multiple
connections selection] to "1".
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 161 When network communication shut-off or communication time-out has occurred [G]
Page 162 When network communication shut-off has occurred [B]
• Disable the forced stop deceleration function for a machine in which multiple axes are connected to each other, such as a
tandem configuration. If an alarm occurs with the forced stop deceleration function disabled, the servo motor will stop with
dynamic brake.
• Turn off EM2 (Forced stop 2), then turn off the servo-on command (from controller) and ready-on command (from
controller). If the ready-on command (from controller) is turned off before EM2 is turned off, the base circuit shut-off delay
and vertical axis freefall prevention do not function.
• 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] [B]

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
PA04.3 *AOP1
PC07 ZSP
PC24 RSBR
Name Outline
Forced stop Set "Forced stop deceleration function" to enabled/disabled.
deceleration function 0: Forced stop deceleration function disabled (EM1 is used)
selection 2: Forced stop deceleration function enabled (EM2 is used) (initial value)
Zero speed Set the level of ZSP (Zero speed detection).
Initial value: 50 [r/min], [mm/s]
Deceleration time Set the deceleration time constant at forced stop.
constant at forced stop Initial value: 100 [ms]
3 BASIC FUNCTION
3.17 Forced stop deceleration function
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