Field set
A field set consists of one or more fields. The fields in a field set
are monitored simultaneously.
A field set can contain various types of field.
A typical application is the use of a protective field with one or
more warning fields: if a vehicle approaches a person, a warning
field triggers an optical or acoustic signal. If the person does not
react to this and the vehicle continues to approach, the safety
laser scanner detects an object in the protective field and
switches the associated safety outputs to the OFF state. The vehi‐
cle stops before it reaches the person.
FPLC
Fail-safe programmable logic controller
Incremental encoder
An incremental encoder generates electrical pulses proportional
to a movement. Various physical quantities can be derived from
these pulses, e.g. speed and distance covered.
Monitoring case
A monitoring case signals the machine status to the safety laser
scanner. The safety laser scanner activates the field set, which is
assigned to the monitoring case and therefore a particular
machine status.
If a machine, e.g., has various operational statuses, a monitoring
case can be assigned to each operational status. The safety laser
scanner receives a defined signal for the current operational sta‐
tus via the control inputs or the network. If there is a change of sig‐
nal, the safety laser scanner switches from one monitoring case to
the monitoring case that is assigned to the new signal (as well as
the new operational status). Generally, one field set is assigned to
each monitoring case.
OFF state
The OFF state is the status of the outputs of the protective device,
where the controlled machine is triggered to quit its dangerous
state and the start-up of the machine is prevented (e.g., the volt‐
age at the OSSDs is LOW, so that the machine is switched off and
remains still).
ON state
The ON state is the status of the outputs of the ESPE, where the
controlled machine is permitted to operate (e.g., the voltage at the
OSSDs is HIGH so that the machine can run).
OSSD
Output signal switching device: signal output for the protective
device, which is used for stopping the dangerous movement.
An OSSD is a safety switching output. The functionality of each
OSSD is tested periodically. OSSDs are always connected in pairs
and must undergo dual-channel analysis for safety reasons. An
OSSD pair is formed from 2 OSSDs that are connected and ana‐
lyzed together.
PFHD
Probability of dangerous failure per hour
PL
Performance level (ISO 13849)
PROFINET
PROFINET (Process Field Protocol) is an Ethernet-based network
used in industrial automation.
With PROFIsafe , PROFINET is also suitable for safety-oriented
data communication.
GLOSSARY
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Subject to change without notice
