5.4 HWBB Function Application Example
5.4.1 Connection Example
5-13
5
S
afety Function
s
5.4
HWBB Function Application Example
This section provides examples of using the HWBB function.
5.4.1
Connection Example
In the following example, a Safety Unit is used as the host controller and the HWBB function
operates when the guard is opened.
When the guard is opened, both the /HWBB1 and the /HWBB2 signals turn OFF, and the
EDM1 signal turns ON. Because the feedback circuit is ON while the guard is closed, the
Safety Unit is reset, the /HWBB1 and the / HWBB2 signals turn ON, and the operation is
enabled.
Note: The EDM1 signal is used as a source output. Connect the EDM1 so that the current flows from EMD1+ to
EMD1-.
5.4.2
Failure Detection Method
If a failure occurs (e.g., the /HWBB1 or the /HWBB2 signal remains ON), the Safety Unit is not
reset when the guard is closed because the EDM1 signal remains OFF. Therefore starting is not
possible and a failure is detected.
In this case the following must be considered: an error in the external device, disconnection of
the external wiring, short-circuiting in the external wiring, or a failure in the SERVOPACK. Find
the cause and correct the problem.
/HWBB1+
4
3
6
5
8
7
A1
A2
T11 T12 T21
T
3
1 T
3
2 T
33
S
24
S
14
T22
/HWBB1-
/HWBB2+
/HWBB2-
EDM1+
EDM1-
0 V
CN8
Clo
s
e
Limit
s
witch
Guard
24-V power
s
upply
Fu
s
e
Open
Power
s
upply
input
Re
s
et/feedback
input
s
Input
s
Output
s
S
ERVOPACK
G9
S
X-BC202
S
afety
Unit manufactured by
OMRON Corporation
