Schweitzer Engineering Laboratories SEL-321 - Operation; Message Decoding and Integrity Checks; Message Transmission

Date Code 20011026 MIRRORED BITS Communications H-3
SEL-321/321-1 Instruction Manual
Mirrored Bits receive default state (string of 1s, 0s or Xs)
87654321
RXDFLT=00000X11
?
Use the RXDFLT setting to determine the default state the MIRRORED BITS should use in place
of received data if an error condition is detected. The setting is a mask of 1s, 0s and/or Xs, for
RMB1 - RMB8, where X represents the most recently received valid value.
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB1PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB1DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB2PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB2DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB3PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB3DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB4PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB4DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB5PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB5DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB6PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB6DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB7PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB7DO= 1 ?
Mirrored Bits RMB_ Debounce PU time (1-8 msgs) RMB8PU= 1 ?
Mirrored Bits RMB_ Debounce DO time (1-8 msgs) RMB8DO= 1 ?
Supervise the transfer of received data (or default data) to RMB1-RMB8 with the MIRRORED
BITS pickup and dropout security counters. Set the pickup and dropout counters individually for
each bit.
For example, any received mirrored bit that is used for direct transfer tripping should have at
least a two received message pickup delay.
OPERATION
Message Transmission
All messages are transmitted without idle bits between characters. Idle bits are allowed between
messages.
· At 4800 baud, one message is transmitted each power system cycle.
· At 9600 baud, one message is transmitted each 1/2 power system cycle.
Message Decoding and Integrity Checks
The relay will deassert a relay element bit, ROK for any of the following reasons:
· Relay disabled.
· M
IRRORED BITS not enabled.