Category – BECKHOFF TwinSAFE User Manual
Page 121
Circuit examples
Application Guide TwinSAFE
119
DC
avg
=
వవ%
భయఱఴ.ళ
ା
వవ%
భళలల.య
ା
వవ%
భళలల.య
ା
వబ%
మళభళ.ర
ା
వవ%
భబమఴ.ఴ
ା
వవ%
భభబఴ.ల
ା
వవ%
వభయ.మ
ା
వవ%
భయఱఴ.ళ
ା
వవ%
భబమఴ.ఴ
ା
వవ%
భబమఴ.ఴ
ା
వవ%
భభబఴ.ల
భ
భయఱఴ.ళ
ା
భ
భళలల.య
ା
భ
భళలల.య
ା
భ
మళభళ.ర
ା
భ
భబమఴ.ఴ
ା
భ
భభబఴ.ల
ା
భ
వభయ.మ
ା
భ
భయఱఴ.ళ
ା
భ
భబమఴ.ఴ
ା
భ
భబమఴ.ఴ
ା
భ
భభబఴ.ల
ൌ 98.62%
Notice
Category
This structure is possible up to category 4 at the most.
MTTF
d
Designation for each channel
Range for each channel
low
3 years
≤
MTTF
d
< 10 years
medium
10 years
≤
MTTF
d
< 30 years
high
30 years
≤
MTTF
d
≤
100 years
DC
avg
Designation
Range
none
DC < 60 %
low
60 %
≤
DC < 90 %
medium
90 %
≤
DC < 99 %
high
99 %
≤
DC
For practical usability, the number of the ranges was limited to four. An accuracy of 5% is assumed for the limit
values shown in this table.
Category
B
1
2
2
3
3
4
DC
MTTF
d
none
none
low
medium
low
medium
high
low
a
-
a
b
b
c
-
medium
b
-
b
c
c
d
-
high
-
c
c
d
d
d
e