GE D90 Plus Instruction Manual page 487

CHAPTER 8: AUTOMATION
Automation math operators
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Table 33: Automation logic Boolean operators and latches
Syntax Description
Logical NOT gate. Operates on the previous
NOT
operand.
to Logical OR gates. Operate on the previous 2 to 16
OR(2) OR(16)
operands.
to Logical AND gates. Operate on the previous 2 to
AND(2) AND(16)
16 operands.
to Logical NOR gates. Operate on the previous 2 to
NOR(2) NOR(16)
16 operands.
to Logical NAND gates. Operate on the previous 2 to
NAND(2) NAND(16)
16 operands.
Logical exclusive OR gate. Operates on the
XOR(2)
previous two operands.
Reset-dominant latch. The operand preceding
LATCH (S,R)
LATCH(S,R)
preceding the reset input is the set input.
Boolean operators perform Boolean logic operations on any digital input or the output of
any preceding logical operator. The output of a logic operator can be used in further logic
processing. The final output of a sequence of logic operations is stored as a virtual digital
output (VDO). The logic operators available in the automation controller are tabulated as
follows.
A latch is asserted on a positive transition of its set input and retains this state until the
positive transition of its reset input. A latch accepts any digital input or the output of any
logical operator to either of its inputs. A total of 256 latches are available in the
Plus
D90 automation controller.
Figure 407: Latch used in automation logic
The table outlines automation logic math syntax. Operators shown with the
operate on two operands, whereas the others operate on one operand.
Table 34: Automation math operators
Syntax Description
Return the absolute value of the previous operand
ABS
Return the arccosine value of the previous operand
ACOS
Add the previous 2 operands
ADD (a, b)
Return the arcsine value of the previous operand
ASIN
Return the arctangent value of the previous operand
ATAN
Return the arctangent value of the first operand divided by the second
ATAN2 (a, b)
operand, with a range of –180 to 180°
Return the smallest integer greater than or equal to the operand
CEIL
Return the cosine value of the previous operand
COS
Divide the first operand by the second operand
DIV(a, b)
Return the power of e (the base of natural logarithms) value of the previous
EXP
operand
is the reset input. The operand
AUTOMATION LOGIC
Output is ON if...
the input is logic 0
any input is logic 1
all inputs are logic 1
all inputs are logic 0
any input is logic 0
only one input is logic 1
there is a positive
transition on the set
input
suffix
(a, b)
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