Paradise P300 SA-bus, Fixed character 06H or 15H, Checksum As Master to Slave, Message Categories

SA-bus

The SA-bus message structure has a different format for messages from Master to Slaves, and from Slaves to Master.

Master to Slave

The message format is:

idle

STX (02H)

Address	Instruction	`Body`	`Body`	`Body`
(31H-61H)	(30H-7FH)	(1st char)	(other chars)	(last char)

ETX (03H)

Checksum

STX:	The fixed character 02H
Address:	Slave Address, range 31H to 6FH (49-11110, ie 63 usable addresses).
Instruction:	Range 30H to 7FH. An ACK or NAK is automatically returned if the instruction is
	received (or there is no response if the message is not received !).
Body:	From zero to 128 characters (resulting in a maximum message length of 132
	characters).
ETX:	The fixed character 03H
Checksum:	The Exclusive OR of the chars from the `STX` to `ETX` inclusive.
Slave to Master
The message format is:

idle

ACK / NAK	Address	Instruction	`Body`	`Body`	`Body`
(06H/15H)	(31H-61H)	(30H-7FH)	(1st char)	(other chars)	(last char)

ETX (03H)

Checksum

ACK/NAK:	The fixed character 06H or 15H
Address:	As Master to Slave
Instruction:	Echo of the instruction to the Slave
Body:	NAK: One character, an echo of the instruction sent.
	ACK: Where no response is expected (ie a `write` message), one character, an
	echo of the instruction sent. Where a response is called for (ie a `query` message
	resulting in a `read` response), the body is as defined for that response.
ETX:	As Master to Slave
Checksum:	As Master to Slave

Message Categories

The remote M&C messages break down into the following categories:

1.Messages to read the configuration & reconfigure the unit

2.Messages to read the fault / operating status / performance of the equipment

3.Messages to read the current test mode & change the test status

4.Messages to request internally calculated values (eg data rates including overhead etc)

5.Messages relating to the remote M&C status

6.Messages relating to queries on the device itself, or option / cards fitted

7.Messages relating to the capabilities of the devices, and remote upgrading.

8.Message to perform an action (eg buffer centre)

9.Messages to change Tx power / carrier in an abbreviated form

10.Messages to read the traffic log

11.Administrative messages

The following table summarises all messages, including the message categories listed above. A detailed list of the content of each message is available on request from Paradise Datacom.

P300H P300 Series Modem Installation and Operating Handbook Page 197