GE T35 Instruction Manual page 139

5 SETTINGS
The logic that determines the interaction of inputs, elements, schemes and outputs is field programmable through the use
of logic equations that are sequentially processed. The use of virtual inputs and outputs in addition to hardware is available
internally and on the communication ports for other relays to use (distributed FlexLogic™).
FlexLogic™ allows users to customize the relay through a series of equations that consist of operators and operands. The
operands are the states of inputs, elements, schemes and outputs. The operators are logic gates, timers and latches (with
set and reset inputs). A system of sequential operations allows any combination of specified operands to be assigned as
inputs to specified operators to create an output. The final output of an equation is a numbered register called a virtual out-
put. Virtual outputs can be used as an input operand in any equation, including the equation that generates the output, as a
seal-in or other type of feedback.
A FlexLogic™ equation consists of parameters that are either operands or operators. Operands have a logic state of 1 or 0.
Operators provide a defined function, such as an AND gate or a Timer. Each equation defines the combinations of parame-
ters to be used to set a Virtual Output flag. Evaluation of an equation results in either a 1 (=ON, i.e. flag set) or 0 (=OFF, i.e.
flag not set). Each equation is evaluated at least 4 times every power system cycle.
Some types of operands are present in the relay in multiple instances; e.g. contact and remote inputs. These types of oper-
ands are grouped together (for presentation purposes only) on the faceplate display. The characteristics of the different
types of operands are listed in the table below.
Table 5–6: T35 FLEXLOGIC™ OPERAND TYPES
OPERAND TYPE STATE
Contact Input On
Off
Contact Output Voltage On
(type Form-A contact
Voltage Off
only)
Current On
Current Off
Direct Input On
Fixed On
Off
Remote Input On
Virtual Input On
Virtual Output On
GE Multilin
EXAMPLE FORMAT CHARACTERISTICS
[INPUT IS '1' (= ON) IF...]
Cont Ip On Voltage is presently applied to the input (external contact
closed).
Cont Ip Off Voltage is presently not applied to the input (external
contact open).
Cont Op 1 VOn Voltage exists across the contact.
Cont Op 1 VOff Voltage does not exists across the contact.
Cont Op 1 IOn Current is flowing through the contact.
Cont Op 1 IOff Current is not flowing through the contact.
DIRECT INPUT 1 On The direct input is presently in the ON state.
On Logic 1
Off Logic 0
REMOTE INPUT 1 On The remote input is presently in the ON state.
Virt Ip 1 On The virtual input is presently in the ON state.
Virt Op 1 On The virtual output is presently in the set state (i.e.
evaluation of the equation which produces this virtual
output results in a "1").
T35 Transformer Management Relay
5.4 FLEXLOGIC™
5
5-61