Siemens S7-300 Installation And Operating Manual page 223

Wire-break check in the range of 0 to 20 mA
In the range 0 to 20 mA, a wire-break check is always performed:
● Wire break at < 0.4442 mA with 7FFF
Wire-break check and underflow check in the range 4 to 20 mA
In the range 4 to 20 mA, a check is made to determine whether wire-break check is
assigned.
● If wire-break check is assigned, an underflow check is not performed. Wire break at < 3,6
● If no wire break is assigned, in case of an underflow at < 0.4444 mA with 8000
Measured value resolution
SM 336; F-AI 6 x 0/4 ... 20 mA HART has a 15-bit resolution.
Table 9- 14
Bit number
Bit significance
Example
Table 9- 15
Measuring range
0 to 20 mA
4 to 20 mA
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
value will be output as configured at the input SUBS_V of the F channel driver. In
Distributed Safety
, the fail-safe value 0 is provided in the PII for the safety program in
place of 7FFF .
H
S7 F/FH Systems
mA with 7FFF in
H
configured at the input SUBS_V of the F channel driver. In
safe value 0 is provided in the PII for the safety program in place of 7FFF
S7 F/FH Systems
is reported and the fail-safe value will be output as configured at the
input SUBS_V of the F channel driver. In
provided in the PII for the safety program in place of 8000
Representation of the bit pattern
15 14
Sig 2
n
0 1
Resolution
S7 F/FH Systems
in
H
is reported and the fail-safe value will be output as
S7 Distributed Safety
13 12 11 10 9
2 2 2 2 2
14 13 12 11 10
0 0 1 1 0
% of nominal range
0,0036
0,0036
9.3 SM 336; F-AI 6 x 0/4 ... 20 mA HART
is reported and the fail-safe
S7 Distributed Safety
, the fail-safe value 0 is
(for underflow).
H
8 7 6 5 4
2 2 2 2 2
9 8 7 6 5
0 1 1 1 1
Resolution
723.4 nA
578.7 nA
Analog modules
S7
, the fail-
.
H
in
H
3 2 1 0
2 2 2 2
4 3 2 1 0
1 1 0 1
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