.. _fsd211:


FSD211: Limited variability language
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The Simplifier system is configured via a block diagram language, which is a limited variability language.

According to 61511-1:

"limited variability language (LVL) this type of language is designed to be comprehensible to process sector users,
and provides the capability to combine predefined, application specific, library functions to implement the safety requirements specifications.
An LVL provides a close functional correspondence with the functions required to achieve the application."

Furthermore, 61511 gives examples:

"NOTE 1 Typical examples of LVL are given in IEC 61131-3. They include ladder diagram, function block diagram and sequential function chart.
NOTE 2 Typical example of systems using LVL: standard PLC (for example, programmable logic controller for burner management)."