Premier Mounts CDM-600 specifications Packet Structure, Start Of Packet, Address

CDM-600 Satellite Modem	Revision 7
Remote Control	MN/CDM600.IOM

16.5Packet Structure

Controller-to-target:

Start of Packet	Target Address	Address	Instruction	Code	Optional	End of Packet
		De-limiter	Code	Qualifier	Arguments
<		/		= or ?		Carriage
ASCII code 60		ASCII code 47		ASCII code		Return
				61 or 63		ASCII code 13
(1 character)	(4 characters)	(1 character)	(3 characters)	(1 character)	(n characters)	(1 character)

	Example:	<0135/TFT=1[CR]
	Target-to-controller:
Start of Packet	Target	Address	Instruction	Code Qualifier	Optional	End of Packet
	Address	De-limiter	Code		Arguments
>		/		=, ?, !, or *		Carriage Return,
ASCII		ASCII		ASCII code 61,		Line Feed
code 62		code 47		63, 33 or 42	(From 0 to n	ASCII code 13,10
(1 character)	(4 characters)	(1 character)	(3 characters)	(1 character)	characters)	(2 characters)

Example: >0654/RSW=32[CR][LF]

Each of the components of the packet is now explained.

16.5.1Start Of Packet

Controller to Target: This is the character ‘<’ (ASCII code 60)

Target to Controller: This is the character ‘>’ (ASCII code 62)

Because this is used to provide a reliable indication of the start of packet, these two characters may not appear anywhere else within the body of the message.

16.5.2Address

Up to 9,999 devices can be uniquely addressed. In EIA-232 applications this value is set to 0. In EIA-485 applications, the permissible range of values is 1 to 9999. It is programmed into a target unit using the front panel keypad.

Important note: The controller sends a packet with the address of a target - the destination of the packet. When the target responds, the address used is the same address, to indicate to the controller the source of the packet. The controller does not have its own address.

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