IFM Electronic Ecomat Mobile Series System Manual page 288

Glossary of Terms
- dependent for its operation on one or more
programmable electronic devices,
- including all elements of the system such as
input and output devices.
Pictogram
Pictograms are figurative symbols which
convey information by a simplified graphic
representation.
→ Chapter What do the symbols and formats
stand for? (→ page 7)
PL
Performance Level
According to ISO 13849-1, a specification
(PL a...e) of safety-related parts of control
systems to perform a safety function under
foreseeable conditions.
PLr
Using the "required performance level" PL
risk reduction for each safety function
according to ISO 13849 is achieved.
For each selected safety function to be carried
out by a SRP/CS, a PL
and documented. The determination of the PL
is the result of the risk assessment and refers
to the amount of the risk reduction.
Pre-Op
Pre-Op = Preoperational mode
Operating status of a CANopen participant.
After application of the supply voltage each
participant automatically passes into this state.
In the CANopen network only SDOs and NMT
commands can be transferred in this mode but
no process data.
prepared
Operating status of a CANopen participant. In
this mode only NMT commands are
transferred.
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ifm System Manual ecomatmobile
the
r
shall be determined
r
SmartController (CR2500) V05
Programming language, safety-
related
Only the following programming languages
shall be used for safety-related applications:
•
Limited variability language (LVL) that
provides the capability of combining
predefined, application-specific library
functions.
In CoDeSys these are LD (ladder diagram)
and FBD (function block diagram).
•
Full variability language (FVL) provides the
capability of implementing a wide variety of
functions.
These include e.g. C, C++, Assembler. In
CoDeSys it is ST (structured text).
► Structured text is recommended
exclusively in separate, certified functions,
usually in embedded software.
► In the "normal" application program only
LD and FBD should be used. The following
minimum requirements shall be met.
In general the following minimum requirements
are made on the safety-related application
software (SRASW):
► Modular and clear structure of the
program. Consequence: simple testability.
► Functions are represented in a
r
comprehensible manner:
- for the operator on the screen
(navigation)
- readability of a subsequent print of the
document.
► Use symbolic variables (no IEC
addresses).
► Use meaningful variable names and
comments.
► Use easy functions (no indirect
addressing, no variable fields).
► Defensive programming.
► Easy extension or adaptation of the
program possible.
Protective measure
Measure intended to achieve risk reduction,
e.g.:
- fault-excluding design,
- safeguarding measures (guards),
- complementary protective measures (user