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5
5.3.3 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.
5.3.4 Safety-related data according to the standard
CAUTION! The relay output is intended only for diagnostics of the STO function.
CAUTION! The relay output is a non-safety-related functionality.
Table 4. Safe Torque Off (STO) safety-related data
MR4 - MR10 MR12
EN 61800-5-2:2007
SIL 3
PFH = 2.5
x10
-10
/hour
HFT = 1
SIL 3
PFH = 3.1x10
-10
/hour
HFT = 1
EN 62061:2005
SIL CL 3
PFH = 2.5
x10
-10
/hour
HFT = 1
SIL CL 3
PFH = 3.1x10
-10
/hour
HFT = 1
EN/ISO 13849-1:2006
PL e
MTTF
d
=2600 years
DC
avg
= medium
Category 3
PL e
MTTF
d
=1100 years
DC
avg
= medium
Category 3
IEC 61508:2010,
High Demand Mode
SIL 3
PFH = 2.5
x10
-10
/hour
HFT = 1
SIL 3
PFH = 3.1
x10
-10
/hour
HFT = 1
IEC 61508:2010,
Low Demand Mode
SIL 3
PFD
AVG
(T
M
)= 2.2x10
-5
T
M
= 20 years
HFT = 1
SIL 3
PFD
AVG
(T
M
)= 2.7x10
-5
T
M
= 20 years
HFT = 1