Siemens SIMOCODE pro System Manual page 680

Glossary
Feedback circuit
Fieldbus
Field/field level
Function block
Independent operation
I/O devices
IT system
Logic module
Glossary-8
Monitors activated actuators (e.g. relays or contactors with
positively-driven contacts). The evaluation unit can only be
activated if the feedback circuit is closed. Note: NC contacts
of the monitored relays that are connected in series are
integrated in the feedback circuit of the safety relay. If a
contact welds in the enabling current path, it is no longer
possible to re-activate the safety relay because the feedback
circuit remains open.
Industrial communication system that connects a multitude
of field devices such as probes (sensors), actuators and
drives with a control device.
The field level or field is separate to the higher-level control
level in automation and the individual sensors and actuators
can be found here.
Defined group of functions that can be freely-parameterized
by the user and connected to other function blocks in order to
create a complete branched logic system. This means
conventional wired control circuits containing auxiliary relays
and time relays can be completely replaced.
SIMOCODE pro C and pro V protect and control the motor
feeder independently of the automation system. Even if the
automation system (PLC) fails, or if communication is
disrupted, the motor feeder remains fully protected and
controllable. SIMOCODE pro can be used without being
connected to PROFIBUS DP . This can easily be connected
later, if required.
The term I/O devices is used in automation to refer to
peripheral devices, for example, devices that are connected
to centralized controls.
The IT system (FR Isolé Terre) is a specific type of ground
connection for increased failsafe protection in case of
isolation faults.
Logical operations, time relay functions and counter functions
are implemented using logic modules.
SIMOCODE pro
GWA 4NEB 631 6050-22 DS 03