User`s manual

4.2 Hard Wire Base Block (HWBB) Function
4-3
4
Safety Function
4.2 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 motor (shut off the motor current) by using
the hardwired circuits: Each circuit for two channel input signals blocks the run sig-
nal to turn off the power module, and the motor current is shut off. (Refer to the dia-
gram below.)
Note: For safety function signal connections, the input signal is the 0V common and the output
signal is the source output. This is opposite to other signals described in this manual. To
avoid confusion, the ON and OFF status of signals for safety functions are defined as fol-
lows:
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 current flows into the signal line.
WARNING
• Perform risk assessment for the system and confirm that the safety requirements
with the following standards are fulfilled before using the HWBB function.
EN954-1 Category3
IEC61508-1 to 4 SIL2
/HWBB1+ 4
3
6
5
/HWBB1-
/HWBB2+
/HWBB2-
0 V
Control circuit
Run signal
SERVOPACK
CN8
Switch
Block
Block
Power module
Power supply
24-V power supply
Fuse
Motor