Packet Structure; Start Of Packet; Target Address - Comtech EF Data CDM-750 Installation And Operation Manual

CDM-750 Advanced High-Speed Trunking Modem
Appendix D
D.5

Packet Structure

Start of Packet

Target Address

<
ASCII code 60
(1 character) (4 characters)
Example: <0000/RSH=30[cr]
Start of Packet Target Address
>
ASCII code 62
(1 character) (4 characters)
Example: >0000/BBU=107[cr][lf]
D.5.1 Start 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.
D.5.2 Target Address
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.
Controller-to-Target
Address Delimiter Instruction Code
/
ASCII code 47
(1 character) (3 characters)
Target-to-Controller
Address Delimiter Instruction Code
/
ASCII code 47
(1 character) (3 characters)
D–3
Optional
Code Qualifier
Arguments
= or ?
ASCII codes
61 or 63
(1 character) (n characters)
Optional
Code Qualifier
Arguments
=, ?, !, or *
ASCII codes
61,63,33 or 42
(From 0 to n
(1 character) characters)
Revision 1
MN-CDM750
End of Packet
Carriage Return
ASCII code 13
(1 character)
End of Packet
Carriage Return,
Line Feed
ASCII codes
13,10
(2 characters)