Schweitzer Engineering Laboratories SEL-421-4, Instruction Manual

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13.32
SEL-400 Series Relays Instruction Manual Date Code 20171006
SEL
OGIC
Control Equation Programming
SEL
OGIC
Control Equation Operators
SIN and COS
Use the SIN or COS operators to calculate the sine or cosine of the argument.
SIN and COS operate in degrees, the unit of angular measure the SEL-451 uses
to express metering quantities.
Example 13.16 shows examples of SIN and COS.
Use parentheses to delimit the argument of a SIN or COS operation.
ASIN and ACOS
Use the ASIN or ACOS operators to calculate the angle resulting from the trigo-
nometric function equivalent to a given number (the argument), where the func-
tion is sine or cosine. ASIN and ACOS operate in degrees. An argument less than
–1 or larger than 1 results in a math error and assertion of the corresponding math
bit described in
Arithmetic on page 13.30 . Example 13.17 shows examples of
ASIN and ACOS. Use parentheses to delimit the argument of an ASIN or ACOS
operation.
# EXP examples
AMV004 := EXP (2) # Calculates e squared
AMV005 := EXP (AMV003) # Calculates e to the power AMV003
AMV006 := EXP ( AMV047) # e raised to the power of the sum
# LOG examples
AMV007 := LOG (AMV012) # Base 10 logarithm of AMV012
AMV008 := LOG ( AMV022) # Base 10 logarithm of the sum
AMV009 := LOG (AMV100) # Produces an error if AMV100 is 0 or
negative
Example 13.15 Using the LN, EXP, and LOG Operators (Continued)
Example 13.16 Using the SIN and COS Operators
The freeform math SEL
OGIC
control equations below are examples of SIN
and COS.
# SIN examples
AMV001 := SIN (AMV005) # Sine of AMV005
AMV002 := SIN ( AMV034) # Sine of the sum
# COS examples
AMV003 := COS (AMV005) # Cosine of AMV005
AMV004 := COS ( AMV006) # Cosine of the sum