IFM Electronic AC5225, Original Device Manual

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ifm Device Manual AS-i IO-Link-Gateway (AC5225) Firmware V1.16 2017-11-20
Glossary of Terms
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R
Redundant
Redundancy is the presence of more than the necessary means so that a function unit performs a
requested function or that data can represent information.
Several kinds of redundancy are distinguished:

Functional redundancy aims at designing safety-related systems in multiple ways in parallel so
that in the event of a
→failure of one component the others ensure the task.

In addition it is tried to separate redundant systems from each other with regard to space. Thus
the
→risk that they are affected by a common interference is minimised.

Finally, components from different manufacturers are sometimes used to avoid that a systematic
fault causes all redundant systems to fail (
→diverse redundancy).
The software of redundant systems should differ in the following aspects:
• specification (different teams),
• specification language,
• programming (different teams),
• programming language,
• compiler.
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remanent
Remanent data is protected against data loss in case of power failure.
The
→runtime system for example automatically copies the remanent data to a →flash memory as
soon as the voltage supply falls below a critical value. If the voltage supply is available again, the
runtime system loads the remanent data back to the RAM memory.
The data in the RAM memory of a controller, however, is volatile and normally lost in case of power
failure.
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RPI
RPI = R equested P acket I ntervall
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RTC
RTC = R eal T ime C lock
Provides (batter-backed) the current date and time. Frequent use for the storage of error message
protocols.
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RTS
RTS = R un t ime S ystem
Runtime systems are basic versions of applications. These minimum versions are supplied with
certain products to meet the prerequisites for the execution of the actual product or to be able to look
at or use results generated by this product on other processors: making available all routines required
to execute a program in a programming language, e.g. interactions with the
→runtime system,
memory requirements, error routines, inputs and outputs.
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Runtime system
Basic program in the device, establishes the connection between the hardware of the device and the
application program.