Siemens SIMATIC ET 200SP Manual page 55

NOTICE
Process value "0" is transmitted as a non-safety related value
Based on the transfer principle of the code sequences, the process value "1" is transferred
via AS-Interface as a safe value, so that the enable for switching on a machine can be
issued in a safety-related manner. If an error occurs during transfer of the value "1", this
error is detected and substitute value "0" is used.
The process value "0" is transferred via AS-interface as an unsafe value. That is, a faulty
transmission of the "0" value cannot be detected. The "0" value must therefore not be used
as safety-related information that initiates a dangerous action (e.g. feedback "0" of a switch
position).
Table 6- 7 Output address assignment in the F-CPU
Byte in Assigned bits in the F-CPU per F-CM AS-i Safety ST module
the F-
Bit 7
CPU
x + 0 DQ0.7
Switching
group 7
x + 1 DQ1.7
Switching
group 15
x + 2 Error
acknowledg
ment for
DQ0.7
x + 3 Error
acknowledg
ment for
DQ1.7
x + 4 Reserved
...
x + 7 Reserved
X = Module start address
The error acknowledgment bit initiates the AUX1 and AUX2 signals one after the other.
Fail-safe Module F‑CM AS‑i Safety ST (3RK7136‑6SC00‑0BC1)
Manual, 03/2017, A5E03957059020A/RS-AB/002
Bit 6 Bit 5
DQ0.6 DQ0.5
Switching Switching
group 6 group 5
DQ1.6 DQ1.5
Switching Switching
group 14 group 13
Error Error
acknowledg acknowledg
ment for ment for
DQ0.6 DQ0.5
Error Error
acknowledg acknowledg
ment for ment for
DQ1.6 D1.5
Assigning parameters / Setting the address space
Bit 4 Bit 3
DQ0.4 DQ0.3
Switching Switching
group 4 group 3
DQ1.4 DQ1.3
Switching Switching
group 12 group 11
Error Error
acknowledg acknowledg
ment for ment for
DQ0.4 DQ0.3
Error Error
acknowledg acknowledg
ment for ment for
DQ1.4 DQ1.3
6.3 Address space
Bit 2 Bit 1
DQ0.2 DQ0.1
Switching Switching
group 2 group 1
DQ1.2 DQ1.1
Switching Switching
group 10 group 9
Error Error
acknowledg acknowledg
ment for ment for
DQ0.2 DQ0.1
Error Error
acknowledg acknowledg
ment for ment for
DQ1.2 DQ1.1
Bit 0
DQ0.0
Switching
group 0
DQ1.0
Switching
group 8
Error
acknowled
gment for
DQ0.0
Error
acknowled
gment for
DQ1.0
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