2 block formation and safety loops, 3 calculation – BECKHOFF TwinSAFE User Manual
Page 104
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Circuit examples
102
Application Guide TwinSAFE
2.17.1 Parameters of the safe input and output terminals
EL1904 (applies to all EL1904 used)
Parameter
Value
Sensor test channel 1 active
Yes
Sensor test channel 2 active
Yes
Sensor test channel 3 active
Yes
Sensor test channel 4 active
Yes
Logic channel 1 and 2
Single Logic
Logic channel 3 and 4
Single Logic
EL2904
Parameter
Value
Current measurement active
Yes
Output test pulses active
Yes
2.17.2 Block formation and safety loops
2.17.2.1 Block 1
2.17.3 Calculation
2.17.3.1 PFH / MTTF
d
/B10
d
– values
Component
Value
EL1904 – PFH
1.11E-09
EL2904 – PFH
1.25E-09
EL6900 – PFH
1.03E-09
S1 – B10
d
1,000,000
S2 – B10
d
2,000,000
K1 – B10
d
1,300,000
K2 – B10
d
1,300,000
Days of operation (d
op
)
230
Hours of operation / day (h
op
)
8
Cycle time (minutes) (T
cycle
)
15 (4x per hour)
Lifetime (T1)
20 years = 175200 hours
K1
K2
EL1904
EL6900
EL2904
S1
S2
K1
K2
EL1904
EL6900
EL2904
S1
S2
EL1904