36
Device Description
WAGO-I/O-SYSTEM 750
753-668/000-004 4FAI 0/4-20 mA Diff PROFIsafe
Manual
Version 1.0.0, valid from HW/SW Version 01/01
3.6.7
Safety Parameters
3.6.7.1
Two-Channel Safety Application
Table 16: Safety Parameters for Two-Channel Safety Application
Maximum safety integrity level per IEC 62061
SIL 3
Maximum safety integrity level per IEC 61508
SIL 3
Maximum performance level
per EN ISO 13849-1
Cat. 4/PL e
Proof test interval/usage duration
20 years
Probability of failure
PFD
AVG
*)
,
Proof test interval
20 years
(low demand mode)
(IEC 61508)
for 1 input pair
(input to fieldbus)
2,45
×
10
−
5
for 2 input pairs in the
same safety function
(input to fieldbus)
2,48
×
10
−
5
Probability of failure
PFH
*)
,
Proof test interval
20 years
(high demand mode)
(IEC 61508)
for 1 input pair
(input to fieldbus)
5
×
10
−
10
1/h
for 2 input pairs in the
same safety function
(input to fieldbus)
5
×
10
−
10
1/h
Hardware fault tolerance HFT
with two-channel application
(IEC 61508)
1
(1 error in the application does
not yet lead to a failure of the
safety equipment)
DC
AVG
(Diagnostic
Coverage Level)
for 1 input pair
(input to fieldbus)
97,84 %
for 2 input pairs in the
same safety function
(input to fieldbus)
97,96 %
MTTF
d
(Mean Time To Failure
dangerous)
for 1 input pair
(input to fieldbus)
698 years
for 2 input pairs in the
same safety function
(input to fieldbus)
631 years
*)
PFD
AVG
: Probability of a dangerous failure on demand
PFH: Probability of a dangerous failure per hour