GE L90 Instruction Manual page 264

5.5 FLEXLOGIC
Therefore, the required logic can be implemented with two FlexLogic equations with outputs of virtual output 3 and vir-
tual output 4 as shown below.
VIRTUAL OUTPUT 1
State=ON
VIRTUAL OUTPUT 2
State=ON
VIRTUAL INPUT 1
State=ON
DIGITAL ELEMENT 1
State=Pickup
DIGITAL ELEMENT 2
State=Operated
CONTACT INPUT H1c
State=Closed
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.
5
3. Prepare a logic diagram for virtual output 4, replacing the logic ahead of virtual output 3 with a symbol identified as vir-
tual 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 out-
put 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.
5-134
Set
LATCH
OR #1 Reset
XOR
Timer 1
Time Delay
AND
on Pickup
(800 ms)
VIRTUAL OUTPUT 3
Figure 5–50: LOGIC EXAMPLE WITH VIRTUAL OUTPUTS
DIGITAL ELEMENT 2
State=Operated
AND(2)
CONTACT INPUT H1c
State=Closed
Figure 5–51: LOGIC FOR VIRTUAL OUTPUT 3
Set
LATCH
OR #1 Reset
XOR
Timer 1
Time Delay
on Pickup
(800 ms)
Figure 5–52: LOGIC FOR VIRTUAL OUTPUT 4
L90 Line Current Differential System
Timer 2
Time Delay
OR #2 VIRTUAL OUTPUT 4
on Dropout
(200 ms)
VIRTUAL OUTPUT 3
827027A2.VSD
Timer 2
Time Delay
OR #2
on Dropout
(200 ms)
5 SETTINGS
827026A2.VSD
VIRTUAL
OUTPUT 4
827028A2.VSD
GE Multilin