Date Code 20080110 Unsolicited SER Protocol F-3
SEL-387E Instruction Manual
functions are enabled. If the SER triggers are disabled, (SER1, SER2, SER3, and SER4 are all
set to NA), the unsolicited SER messages are still enabled, but the only SER records generated
are due to settings changes and power being applied to the relay. If the SER1, SER2, SER3, or
SER4 settings are subsequently changed to any non-NA value and SER entries are triggered,
unsolicited SER messages will be generated with the new SER records.
0x02—Function Code: Disable Unsolicited Data Transfer
This function disables the SEL-387E Relay from transferring unsolicited data. The message
format for function code 0x02 is shown below.
Data
Description
A546 Message header
10 Message length (16 decimal)
0000000000 Five bytes reserved for future use as a routing address.
YY Status byte (LSB = 1 indicates an acknowledge is requested)
02 Function code
C0 Sequence byte (Always C0. Other values are reserved for future use in
multiple frame messages.)
XX Response number (XX = 00, 01, 02, 03, 01, 02...)
18 Function to disable (0x18 = Unsolicited SER)
00 Reserved for future use as function code data
cccc Two byte CRC-16 check code for message
The SEL-387E Relay verifies the message by checking the header, length, function code, and
disabled function code against the expected values, and checks the entire message against the
CRC-16 field. If any of the checks fail, except the function code or the function to disable, the
message is ignored.
If an acknowledge is requested as indicated by the least significant bit of the status byte, the
relay transmits an acknowledge message with the same response number received in the enable
message.
If the function to disable is not 18 or the function code is not recognized, the relay responds with
an acknowledge message containing the response code 01 (function code unrecognized) and no
functions are disabled.
0x18—Function: Unsolicited Sequential Events Response
The function 0x18 is used for the transmission of unsolicited Sequential Events Recorder (SER)
data from the SEL-387E Relay. This function code is also passed as data in the “Enable
Unsolicited Data Transfer” and the “Disable Unsolicited Data Transfer” messages to indicate
which type of unsolicited data should be enabled or disabled. The message format for function
code 0x18 is shown below.
Data
Description
A546 Message header
ZZ Message length (Up to 34 + 4 • nn decimal, where nn is the maximum number
of SER records allowed per message as indicated in the "Enable Unsolicited
Data Transfer" message.)
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