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U.3.14
SEL-421/SEL-421-1 Relay
User’s Guide
Date Code 20020501
PC Software
Expression Builder
Using the
Expression Builder
For Protection Free-Form SEL
OGIC
and Automation Free Form SEL
OGIC
,
select the type of result (LVALUE) for the SEL
OGIC
control equation to use
the Expression Builder. The
AC
SEL
ERATOR
software shows these possibilities
in the file box directly underneath the left side of the equation. The program
shows the relay elements for each type of SEL
OGIC
control equation (Boolean
Variables, Math Variables, etc.).
On the right side of the equation (RVALUE), you can select broad categories
of relay elements, analog quantities, counters, timers, latches, Boolean
variables, and math variables. Select a category in the RVALUE tree view, and
the Expression Builder displays all elements for that category in the list box at
the bottom right side.
Directly underneath the right side of the equation, you can choose operations
to include in the RVALUE. These operations include basic logic functions,
rising and falling edge triggers, expression compares, and math functions.
For more information on programming SEL
OGIC
control equations, see
Summary of Contents for SEL-421
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