Application Example Of Safety Functions - YASKAWA SGDV series User Manual

4.7.3 Application Example of Safety Functions

An example of using safety functions is shown below.
(1) Connection Example
In the following example, a safety unit is used and the HWBB function operates when the guard opens.
Guard
24-V power
supply
0 V
When a guard opens, both of signals, the /HWBB1 and the /HWBB2, turn OFF, and the EDM1 signal turns
ON. Since the feedback is ON when the guard closes, the safety unit is reset, and the /HWBB1 and the /
HWBB2 signals turn ON, and the operation becomes possible.
Note: The EDM1 signal is used as a sourcing output. Connect the EDM1 so that the current flows from EMD1+ to EMD1-.
(2) Failure Detection Method
In case of a failure such as the /HWBB1 or the /HWBB2 signal remains ON, the safety unit is not reset when
the guard closes because the EDM1 signal keeps OFF. Therefore starting is impossible, then the failure is
detected.
In this case, an error in the external device, disconnection or short-circuiting of the external wiring, or a failure
in the SERVOPACK or converter must be considered. Find the cause and correct the problem.
Close
Limit switch
Open
Fuse
A1 T11 T12 T21 T22
Input
Power
supply
Reset/feedback
input
input
A2 T31 T32 T33
Safety unit G9SX-BC202
manufactured by OMRON Corp.
Output
SERVOPACK
S24 S14
CN8
/HWBB1+
4
/HWBB1-
3
/HWBB2+
6
/HWBB2- 5
EDM1+ 8
7
EDM1-
4.7 Safety Function
4
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