Schweitzer Engineering Laboratories SEL-387E - Automatic Messages; Event Summary Message; Relay Self-Test Warning or Failure; Relay Startup Message

7-12 Communications Date Code 20080110
SEL-387E Instruction Manual
Each message begins with the start-of-transmission character STX (ASCII character 02) and
ends with the end-of-transmission character ETX (ASCII character 03).
3. The relay indicates how full its receive buffer is through an XON/XOFF protocol.
The relay transmits XON (ASCII hex 11) when the buffer drops below 40 percent full.
The relay transmits XOFF (ASCII hex 13) when the buffer is over 80 percent full.
Automatic transmission sources should monitor for the XOFF character so they do not
overwrite the buffer. Transmission should terminate at the end of the message in progress
when XOFF is received and may resume when the relay sends XON.
4. You can use an XON/XOFF procedure to control the relay during data transmission. When
the relay receives an XOFF command during transmission, it pauses until it receives an
XON command. If there is no message in progress when the relay receives an XOFF
command, it blocks transmission of any message presented to its buffer.
The CAN character (ASCII hex 18) aborts a pending transmission. This is useful in
terminating an unwanted transmission.
5. Control characters can be sent from most keyboards with the following keystrokes:
XON: <Ctrl + Q> (hold down the Control key and press Q)
XOFF: <Ctrl + S> (hold down the Control key and press S)
CAN: <Ctrl + X> (hold down the Control key and press X)
Automatic Messages
The SEL-387E Relay generates automatic messages and sends them out the serial port(s) with
the SET P setting AUTO = Y. Four different automatic messages can be displayed:
• Relay startup message
• Setting group change message
• Relay self-test warning or failure
• Event summary message
Relay Startup Message
Immediately after power is applied, the relay transmits the following automatic message:
XFMR 1 Date: MM/DD/YY Time: HH:MM:SS.SSS
STATION A
SEL-387E
=
Setting Group Change Message
The SEL-387E Relay has six different setting groups for the SET settings. The active group is
selected by the SS1 through SS6 SEL
OGIC
®
control equation variable bits, or by the GRO n
serial port command, or the front-panel GROUP pushbutton. At the moment when the active
group is changed, the following automatic message is generated.