Schweitzer Engineering Laboratories SEL-311C - Acknowledge Message Sent from Master to Relay, and from Relay to Master

K.7
Date Code 20060320 Instruction Manual SEL-311C Relay
Unsolicited Fast SER Protocol
Functions and Function Codes
Acknowledge
Message Sent From
Master to Relay, and
From Relay to Master
The acknowledge message is constructed and transmitted for every received
message which contains a status byte with the LSB set (except another
acknowledge message), and which passes all other checks, including the CRC.
The acknowledge message format is shown in Table K .5.
The SEL-311C supports the response codes shown in Table K.6.
Examples
1. Successful acknowledge for “Enable Unsolicited Data
Transfer” message from a relay with at least one of SER1,
SER2, or SER3 not set to NA.
A5 46 0E 00 00 00 00 00 00 81 00 XX cc cc
(XX is as same as the Response Number in the “Enable
Unsolicited Data Transfer” message to which it responds.)
2. Unsuccessful acknowledge for “Enable Unsolicited Data
Transfer” message from a relay with all of SER1, SER2, and
SER3 set to NA.
A5 46 0E 00 00 00 00 00 00 81 02 XX cc cc
(XX is as same as the response number in the “Enable
Unsolicited Data Transfer” message to which it responds.)
00000000 Element status (unused)
cccc Two byte CRC-16 checkcode for message
Table K.4 Format of Message if SER Records Have Been Lost (Sheet 2 of 2)
Data Description
Table K.5 Acknowledge Message
Data Description
A546 Message header
0E Message length (14 decimal)
0000000000 Five bytes reserved for future use as a routing address.
00 Status byte (always 00)
XX Function code, echo of acknowledged function code with MSB set.
RR Response code (see below)
XX Response number (XX = 00, 01, 02, 03, 00, 01, ...) must
match response number from message being acknowledged.
cccc Two byte CRC-16 checkcode for message
Table K.6 Response Codes
RR Response
00 Success.
01 Function code not recognized.