Sel 2414 - SEL OGIC Control Equation Operators; Operator Precedence

4.9
Date Code 20130214 Instruction Manual SEL-2414 Transformer Monitor
Logic Functions
SELOGIC Control Equation Operators
SELOGIC Control Equation Operators
Use the Boolean operators to combine values with a resulting Boolean value.
Edge trigger operators provide a pulse output. Combine the operators and oper-
ands to form statements that evaluate complex logic. SEL
OGIC control equations
are either Boolean type or math type. Because the equals sign (=) is already used
as an equality comparison, both Boolean type and math type of SEL
OGIC control
equation settings begin with an “assignment” operator (:=) instead of with an
equals sign.
Boolean SEL
OGIC control equation settings use logic similar to Boolean algebra
logic, combining Device Word bits together with one or more of the Boolean
operators listed in Table 4.8. Math SEL
OGIC control equation settings operate on
numerical values, using one or more of the Mathematical operators listed in
Table 4.8. These numerical values can be mathematical variables or actual real
numbers.
Operator Precedence
When you combine several operators and operands within a single expression,
the SEL-2414 evaluates the operators from left to right, starting with the highest
precedence operators and working down to the lowest precedence.
Parentheses Operator ( )
You can use more than one set of parentheses in a SELOGIC control equation set-
ting. Use as many as 14 sets of parentheses in a single SEL
OGIC control equation
setting. The parentheses can be “nested” (parentheses within parentheses).
Tab le 4. 8 S E LOGIC Control Equation Operators (Listed in Operator Precedence)
Operator Function
Function Type
(Boolean and/or Mathematical)
( ) Parentheses Boolean and Mathematical
(highest precedence)
– Negation Mathematical
NOT NOT Boolean
R_TRIG Rising edge trigger/detect Boolean
F_TRIG Falling edge trigger/detect Boolean
*
/
Multiply
Divide
Mathematical
Mathematical
+
-
Add
Subtract
Mathematical
Mathematical
<, >, <=, >= Comparison Boolean
=
<>
Equality
Inequality
Boolean
Boolean
AND AND Boolean
OR OR Boolean (lowest precedence)