GE D90 Plus Instruction Manual page 325

CHAPTER 7: PROTECTION
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
RX1, RX2, RX3, RX4
Range: any FlexLogic operand
Default: OFF
These settings select FlexLogic operands to represent the permission receive signals for
the scheme. Contact inputs interfacing with a signaling system typically are used. These
settings must be used in conjunction with the loss-of-guard signals, otherwise the
scheme does not unblock and thus fails to operate. These settings are used as follows:
– In single-bit applications,
– In two-bit applications,
– In four-bit applications,
Loss of Guard 1, Loss of Guard 2, Loss of Guard 3, Loss of Guard 4
Range: any FlexLogic operand
Default: OFF
These settings select FlexLogic operands to represent the loss-of-guard receive signals
for the scheme. Contact inputs interfacing with a signaling system typically are used.
Each loss-of-guard signal must correspond to the same receive signal from the same
communications channel (that is,
communications channel, and the same for channels 2, 3 and 4, if used). These settings
are used as follows:
– In single-bit applications,
– In two-bit applications,
must be used
– In four-bit applications, all receive and loss-of-guard signals must be used
Events
Range: Enabled, Disabled
Default: Enabled
This setting enables and disables the logging of directional comparison unblocking
scheme events in the sequence of events recorder.
The figures show the directional comparison unblocking scheme logic.
must be used
RX1
and must be used
RX1 RX2
through must be used
RX1 RX4
and
RX1 Loss of Guard 1
and
Loss of Guard 1 RX1
with and
Loss of Guard 1 RX1
CONTROL ELEMENTS
must be from the same
must be used
with
Loss of Guard 2 RX2
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