Automation Operators - GE D90 Plus Instruction Manual

AUTOMATION LOGIC

Automation operators

About Boolean operators and latches
420
The following operators are available for the creation of automation logic.
• One-shots.
• Boolean operators and latches.
• Math operators.
• Virtual outputs.
• Comparators.
• Timers.
Unlike earlier versions of the D90
latches and not through the specific setting menus.
The following sub-sections provide additional detail on these operators.
The Boolean logic and latch syntax is shown in the following table.
Table 34: 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. Operates on the previous 2 to
AND(2) AND(16)
16 operands.
to Logical NOR gates. Operates on the previous 2 to
NOR(2) NOR(16)
16 operands.
to Logical NAND gates. Operates on the previous 2
NAND(2) NAND(16)
to 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 may 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
below.
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 342: Latch used in automation logic
Plus
, automation timers are implemented like gates or
is the reset input. The operand
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 8: AUTOMATION
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