Vacon optbj, Safety Manual

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5
vacon • 26 STO and SS1 safety functions
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5.3.6 Relay output
When the STO function is active, the relay output is closed. When the STO function is inactive the
relay output is open. When STO function has detected a non-resettable diagnostics fault the relay
output toggles at a frequency of one hertz.
NOTE! The ATEX input has no effect on the relay output.
Table 7. STO function truth table
V
STO1+
- V
STO1-
V
STO2+
- V
STO2-
STO state
0VDC 0VDC STO active
24VDC 0VDC
STO diagnostic fault and STO activation. Fault is activated after
inputs have been in different states for >500 ms.
0VDC 24VDC
STO diagnostic fault and STO activation. Fault is activated after
inputs have been in different states for >500 ms.
24VDC 24VDC STO inactive
CAUTION! The relay output is intended only for diagnostics of the STO function.
CAUTION! The relay output is a non-safety-related functionality.
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