1 start of packet, 2 target address, 3 address delimiter – Comtech EF Data CDM-570A User Manual
Page 244: 4 instruction code, 5 instruction code qualifier

CDM-570A/570AL Satellite Modem with Optional Packet Processor
MN-CDM570A
Serial-based Remote Product Management
Revision 2
8–4
8.2.2.1 Start of Packet
•
Controller-to-Target: This is the character ‘<’ (ASCII code 60).
•
Target-to-Controller: This is the character ‘>’ (ASCII code 62).
The ‘<’ and ‘>’ characters indicate the start of packet. They may not appear anywhere else within the body of the message.
8.2.2.2 Target Address
Up to 9999 devices can be uniquely addressed. In EIA-232 applications this value is set to 0000. In EIA-485 applications, the permissible
range of values is 0001 to 9999. It is programmed into a Target unit using the front panel keypad.
The Target Address designates the packet destination. The Controller does not have its own address. After the Controller sends a packet
with the designated Target Address, the Target responds to the Controller, using this same address, to indicate the source of the packet.
8.2.2.3 Address Delimiter
This is the “forward slash” character '/ ' (ASCII code 47).
8.2.2.4 Instruction Code
This is a three-character alphanumeric sequence that identifies the message subject. Uppercase alphabetic characters (‘A’ to ‘Z’, ASCII
Codes 65 to 90) and the numbers ‘0’ to ‘9’ *ASCII Codes 48 to 57) may be used. Wherever possible, each instruction code is named to
serve as a mnemonic for its intended operation. This helps you interpret the code function, should it be shown in its raw ASCII form.
For example: MLC for Management Link Configuration, IPA for Management IP Address, etc.
8.2.2.5 Instruction Code Qualifier
This is a single character that further qualifies the preceding instruction code.