GE 889 - Page 511

CHAPTER 4: SETPOINTS FLEXLOGIC
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 4–381
The characteristics of the logic gates are tabulated below, and the operators available in
FlexLogic™ are listed in the FlexLogic™ operators table.
Table 4-39: FlexLogic Gate Characteristics
One-shot POSITIVE ONE SHOT One shot that responds
to a positive going edge.
A ‘one shot’ refers to a
single input gate that
generates a pulse
response to an edge on
the input. The output
from a ‘one shot’ is True
(positive) for only one
pass through the
FlexLogic equation. There
is a maximum of 64 ‘one
shots’.
NEGATIVE ONE
SHOT
One shot that responds
to a negative going
edge.
DUAL ONE SHOT One shot that responds
to both the positive and
negative going edges.
Logic gate NOT Logical NOT Operates on the previous
parameter.
OR(2)↓ OR(16) 2 input OR gate↓ 16
input OR gate
Operates on the 2
previous parameters.
↓Operates on the 16
previous parameters.
AND(2)↓ AND(16) 2 input AND gate↓ 16
input AND gate
Operates on the 2
previous parameters.
↓Operates on the 16
previous parameters.
NOR(2)↓ NOR(16) 2 input NOR gate↓ 16
input NOR gate
Operates on the 2
previous parameters.
↓Operates on the 16
previous parameters.
NAND(2)↓ NAND(16) 2 input NAND gate↓ 16
input NAND gate
Operates on the 2
previous parameters.
↓Operates on the 16
previous parameters.
XOR(2) 2 input Exclusive OR gate Operates on the 2
previous parameters.
LATCH (S,R) Latch (set, reset): reset-
dominant
The parameter preceding
LATCH(S,R) is the reset
input. The parameter
preceding the reset input
is the set input.
Timer TIMER 1↓ TIMER 32 Timer set with
FlexLogic™ timer 1
settings. ↓ Timer set with
FlexLogic™ timer 32
settings.
The timer is started by
the preceding parameter.
The output of the timer is
TIMER #.
Assign virtual output = Virt Op 1↓ = Virt
Op 32
Assigns previous
FlexLogic™ operand to
virtual output 1.↓ Assigns
previous FlexLogic™
operand to virtual output
96.
The virtual output is set
by the preceding
parameter
GATES NUMBER OF INPUTS OUTPUT IS ‘1’ (= ON) IF...
NOT 1 input is ‘0’
OR 2 to 16 any input is ‘1’
AND 2 to 16 all inputs are ‘1’
NOR 2 to 16 all inputs are ‘0’
NAND 2 to 16 any input is ‘0’
XOR 2 only one input is ‘1’
TYPE SYNTAX DESCRIPTION NOTES