GE L90 Instruction Manual page 155

5 SETTINGS
2. Prepare a logic diagram for the equation to produce Virtual Output 3, as this output will be used as an operand in the
Virtual Output 4 equation (create the equation for every output that will be used as an operand first, so that when these
operands are required they will already have been evaluated and assigned to a specific Virtual Output). The logic for
Virtual Output 3 is shown below with the final output assigned.
DIGITAL ELEMENT 2
State=Operated
CONTACT INPUT H1c
State=Closed
3. Prepare a logic diagram for Virtual Output 4, replacing the logic ahead of Virtual Output 3 with a symbol identified as
Virtual Output 3, as shown below.
VIRTUAL OUTPUT 1
State=ON
VIRTUAL OUTPUT 2
State=ON
VIRTUAL INPUT 1
State=ON
DIGITAL ELEMENT 1
State=Pickup
VIRTUAL OUTPUT 3
State=ON
CONTACT INPUT H1c
State=Closed
4. Program the FlexLogic™ equation for Virtual Output 3 by translating the logic into available FlexLogic™ parameters.
The equation is formed one parameter at a time until the required logic is complete. It is generally easier to start at the
output end of the equation and work back towards the input, as shown in the following steps. It is also recommended to
list operator inputs from bottom to top. For demonstration, the final output will be arbitrarily identified as parameter 99,
and each preceding parameter decremented by one in turn. Until accustomed to using FlexLogic™, it is suggested that
a worksheet with a series of cells marked with the arbitrary parameter numbers be prepared, as shown below.
5. Following the procedure outlined, start with parameter 99, as follows:
99: The final output of the equation is Virtual Output 3, which is created by the operator "= Virt Op n". This parameter
is therefore "= Virt Op 3."
GE Multilin
AND(2)
Figure 5–26: LOGIC FOR VIRTUAL OUTPUT 3
Set
LATCH
OR #1 Reset
XOR
Timer 1
Time Delay
on Pickup
(800 ms)
Figure 5–27: LOGIC FOR VIRTUAL OUTPUT 4
01
02
03
04
05
97
98
99
Figure 5–28: FLEXLOGIC™ WORKSHEET
L90 Line Differential Relay
VIRTUAL OUTPUT 3
827027A2.VSD
Timer 2
Time Delay
OR #2
on Dropout
(200 ms)
827029A1.VSD
5.4 FLEXLOGIC™
VIRTUAL
OUTPUT 4
5
827028A2.VSD
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