ABB REL 551-C1*2.5, Technical Reference Manual, Page: 12 / 170

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Introduction to the technical reference manual Chapter 1
Introduction
Functionality/Design
Presents the general concept of a function.
Function block
Each function block is imaged by a graphical symbol.
Input signals are always on the left side, and output signals on the right side. Settings are not
displayed. A special kind of settings are sometimes available. These are supposed to be connect-
ed to constants in the configuration scheme, and are therefore depicted as inputs. Such signals
will be found in the signal list but described in the settings table.
Figure 1: Function block symbol example
Logic diagram
The description of the design is chiefly based on simplified logic diagrams, which use IEC sym-
bols, for the presentation of different functions, conditions etc. The functions are presented as a
closed block with the most important internal logic circuits and configurable functional inputs
and outputs.
Completely configurable binary inputs/outputs and functional inputs/outputs enable the user to
prepare the REx 5xx with his own configuration of different functions, according to application
needs and standard practice.
xx00000207.vsd
T UV
BLOCK
BLKTR
VTSU TRIP
STL1
STL2
STL3
START