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11 Supplement
VEGAPULS 68 • Foundation Fieldbus
36538-EN-170405
and is used universally. PID blocks can be cascaded if this is necessary or requested due to differ-
ent time constants with the primary and secondary process measurement.
Fig. 60: Schematic presentation function block PID Control
Function block Output Splitter
The function block "
Output Splitter
" generates two control outputs out of one input. Each output is
a linear image of a part of the input. A retrograde calculation function is realised by using the linear
imaging function inversely. A cascading of several Output Splitters is supported by an integrated
decision table for the combinability of inputs and outputs.
Fig. 61: Schematic presentation function block Output Splitter
Function block Signal Characterizer
The function block "
Signal Characterizer
" has two channels the outputs of which are not in linear
relation with the respective input. The non-linear relation is defined by a look-up table with individu-
ally selectable x/y-pairs. The respective input signal is imaged on the corresponding output, hence
this function block can be used in a control loop or signal path. Optionally the function axis can be
exchanged in channel 2 so that the block can be also used in a reverse control loop.