Sel 421 - Figure 3.17 Location of the Expression Builder Option Buttons

U.3.15
Date Code 20090715 User’s Guide SEL-421 Relay
PC Software
Expression Builder
Figure 3.17 Location of the Expression Builder Option Buttons
Expression Builder
Organization
The Expression Builder dialog box is organized into two main parts
representing the left side (LVALUE) and right side (RVALUE) of the
SEL
OGIC control equation. (The LVALUE is fixed for all settings except
Protection Free-Form SEL
OGIC and Automation Free Form SELOGIC settings;
see Fixed SEL
OGIC Control Equations on page R.3.4.)
Figure 3.18 shows the two sides of the Expression Builder, with the
SEL
OGIC control equation that you are constructing at the top of the dialog
box. Note the dark vertical line and the equals sign (:=) separating the
equation left and right sides.
Figure 3.18 The ACSELERATOR QuickSet Expression Builder
Using the Expression
Builder
For Protection Free-Form SELOGIC and Automation Free Form SELOGIC,
select the type of result (LVALUE) for the SEL
OGIC control equation to use
the Expression Builder.
ACSELERATOR QuickSet 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.
Courtesy of NationalSwitchgear.com