Analog modules
9.3 SM 336; F-AI 6 x 0/4 ... 20 mA HART
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
277
Example
The following figure shows you the behavior of the discrepancy evaluation when standard
value = MAX.
The diagram above shows you the characteristic curve of the two process values. The
dashed line represents the absolute tolerance range configured in this example.
The lower diagram shows you the standard value signaled to the F-CPU.
In this example, on the first occurrence of a discrepancy, process value 1 is
within the
tolerance range again
before expiration of the discrepancy time. This means the discrepancy
is not signaled.
In this example, on the second occurrence of a discrepancy, process value 1 is
outside the
tolerance range when the discrepancy time expires. As a result, a discrepancy is signaled
with 7FFF
H
after expiration of the discrepancy time. In
S7 Distributed Safety, the fail-safe
value 0 is provided in the PII for the safety program in place of 7FFF
H
. In
S7 F/FH Systems
the fail-safe value assigned at the input SUBS_V of the channel driver will be provided in the
PII.
'LVFUHSDQF\WLPH
DFWLYH
'LVFUHSDQF\WLPH
DFWLYH
3URFHVVGDWD
3URFHVVGDWD
6WDQGDUG
YDOXH
'LVFUHSDQF\
1RORQJHU
GLVFUHSDQW
'LVFUHSDQF\
'LVFUHSDQF\WLPH
HODSVHG
,>P$@
,>P$@
)))
+
W
W
