Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - MECHATROLINK-II Communications Reference - Manual (Page 142)

4.9 Safety Function
4-57
4
Ope
rat
ion
4.9 Safety Function
The safety function is incorporated in the SERVOPACK to reduce the risk associated with the machine by pro-
tecting workers from injury and by securing safe machine operation. Especially when working in hazardous
areas inside the safeguard, as for machine maintenance, it can be used to avoid adverse machine movement.
4.9.1 Hard Wire Base Block (HWBB) Function
The Hard Wire Base Block function (hereinafter referred to as HWBB function) is a safety function designed
to baseblock the servomotor (shut off the motor current) by using the hardwired circuits. Each circuit for two
channel input signals blocks the run signal to turn off the power module that controls the motor current, and
the motor current is shut off. (Refer to the diagram below.)
For safety function signal connections, the input signal is the 0 V common and the output
signal is the source output. This is the opposite of other signals described in this manual.
To avoid confusion, the ON and OFF status of signals for safety functions are defined as
follows:
ON: The state in which the relay contacts are closed or the transistor is ON and current
flows into the signal line.
OFF: The state in which the relay contacts are open or the transistor is OFF and no cur-
rent flows into the signal line.
CN8
/HWBB1+ 4
3
6
5
/HWBB1-
/HWBB2+
/HWBB2-
0 V
SERVOPACK
Switch
Block
Block
Power module
Power supply
24-V power supply
Fuse
Motor
Control circuit
Run
signal