12.4 Applications Examples for Safety Functions
12.4.1 Connection Example
12-12
12.4
Applications Examples for Safety Functions
This section provides examples of using the safety functions.
12.4.1
Connection Example
In the following example, a Safety Unit is used and the HWBB 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-.
12.4.2
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
T31 T32 T33
S24 S14
T22
/HWBB1-
/HWBB2+
/HWBB2-
EDM1+
EDM1-
0 V
CN8
Close
Limit switch
Guard
24-V power
supply
Fuse
Open
Power
supply
input
Reset/feedback
inputs
Inputs
Outputs
SERVOPACK
G9SX-BC202 Safety
Unit manufactured by
OMRON Corporation
