5.2 HWBB Function
5.2.10 /BK (Brake Output) Signal
5-11
5
S
afety Function
s
5.2.10
/BK (Brake Output) Signal
If the HWBB function operates when the /HWBB1 or /HWBB2 signal is OFF, the /BK (Brake)
signal will turn OFF. At that time, the setting in Pn506 (Brake Reference - Servo OFF Delay
Time) will be disabled. Therefore, the Servomotor may be moved by external force until the
actual brake becomes effective after the /BK signal turns OFF.
5.2.11
Stopping Methods
If the /HWBB1 or /HWBB2 signal turns OFF and the HWBB function operates, the Servomotor
will stop according to the stop mode that is set for stopping the Servomotor when the servo
turns OFF (Pn001 = n.
X). However, if the dynamic brake is enabled (Pn001 = n.
0 or
n.
1), observe the following precautions.
5.2.12
ALM (Servo Alarm) Signal
The ALM (Servo Alarm) signal is not output in the HWBB state.
C
A
UTION
The brake signal is not a safety-related element. You must design the system so that a haz-
ardous condition does not occur even if the brake signal fails in the HWBB state. Also, if a
Servomotor with a Brake is used, keep in mind that the brake in the Servomotor is used only
to prevent the moving part from being moved by gravity or an external force and it cannot
be used to stop the Servomotor.
C
A
UTION
The dynamic brake is not a safety-related element. You must design the system so that a
hazardous condition does not occur even if the Servomotor coasts to a stop in the HWBB
state. Normally, we recommend that you use a sequence that returns to the HWBB state
after stopping for a reference.
If the application frequently uses the HWBB function, stopping with the dynamic brake may
result in the deterioration of elements in the SERVOPACK. To prevent internal elements from
deteriorating, use a sequence in which the HWBB state is returned to after the Servomotor
has come to a stop.
