GE D90 Plus Instruction Manual page 395

CHAPTER 7: PROTECTION
NOTE:
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 324: Protection virtual inputs configuration settings
The following settings are available for each protection virtual input. The default values
outlined are for virtual input 1.
Function
Range: Enabled, Disabled
Default: Disabled
If this setting is "Disabled," the virtual input is forced to off (logic 0) regardless of any
attempt to alter the input. If set to "Enabled," the input operates as shown on the logic
diagram and generates output logic operands in response to received input signals and
the applied settings.
ID
Range: up to 12 alphanumeric characters
Default: Virt Ip 1
This setting specifies an identifier that can be assigned to each virtual input.
Type
Range: Self-Reset, Latched
Default: Latched
There are two types of operation: self-reset and latched. If this setting is "Self-Reset," the
output operand is asserted (logic 1) for only one evaluation of the protection FlexLogic
equations and then returns to 0 when the input signal transits from off to on. If set to
"Latched," the virtual input sets the state of the output operand to the same state as the
most recent received input.
The self-reset operating mode generates an output operand for a single evaluation of
FlexLogic equations. If the operand is to be used anywhere other than internally in an
automation logic equation, it likely will have to be lengthened in time. A FlexLogic timer
with a delayed reset can perform this function.
Events
Range: Enabled, Disabled
Default: Disabled
When this setting is "Enabled," every change in the protection virtual input state triggers
an event in the sequence of events recorder.
The figure shows the protection virtual input logic. The logic is identical for all protection
virtual inputs.
PROTECTION INPUTS AND OUTPUTS
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