Siemens S7-300 - Glossary

Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
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Glossary
1oo1 evaluation
Type of → sensor evaluation: In 1oo1 evaluation, the → sensor is not redundant and is
connected via one channel to the module.
1oo2 evaluation
Type of → sensor evaluation: In 1oo2 evaluation, two input channels are occupied, either by
one two-channel sensor or two single-channel sensors. The input signals are compared
internally for equivalence or nonequivalence. Alternatively, the 1oo2 evaluation in
S7 F
Systems
can be made with F-block F_1oo2AI.
2oo3 evaluation
Type of → sensor evaluation: In 2oo3 evaluation, three input channels are occupied by
single-channel sensors. The input signals undergo a 2oo3 evaluation in the safety program
with a F_2oo3AI block in
S7 F Systems .
Acknowledgment time
Interval within which the → F-I/O acknowledges the sign-of-life signal output by the → F-CPU.
The acknowledgment time is included in the calculation of the → monitoring time and →
response time of the entire F-system.
Actuator
Denotes, for example, power relays or relay contactors for switching loads, or the actual load
(for example, directly controlled solenoid valves).
Availability
Probability that a system is functional at a defined point in time. Can be enhanced by means
of -> redundancy (for example, by using redundant signal modules and/or multiple → sensors
at the same measuring point).
Category
Category to EN 954-01
The -> fail-safe signal modules support up to category 4 when operated in safety mode.
Channel fault
Channel-specific fault such as wire break or short-circuit.