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C.5 packet structure, C.5.1 start of packet – Comtech EF Data SLM-5650A User Manual

Page 355

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SLM-5650A Satellite Modem

Revision 8

Appendix C

MN-SLM5650A

C–3

C.5

Packet Structure

Controller-to-Target

Start of Packet

Target Address

Address Delimiter

Instruction Code

Code Qualifier

Optional Arguments

End of Packet

<

ASCII code 60

(1 character)

(4 characters)

/

ASCII code 47

(1 character)

(3 characters)

= or ?

ASCII codes 61 or

63

(1 character)

(n characters)

Carriage Return

ASCII code 13

(1 character)

Example:

<0135/TFQ=70.2345{CR}

Target-to-Controller

Start of Packet

Target Address

Address Delimiter

Instruction Code

Code Qualifier

Optional Arguments

End of Packet

>

ASCII code 62

(1 character)

(4 characters)

/

ASCII code 47

(1 character)

(3 characters)

=, ?, !, or *

ASCII codes

61, 63, 33, or 42

(1 character)

(From 0 to n

characters)

Carriage Return,

Line Feed

ASCII codes 13,10

(2 characters)

Example:

>0654/RSW=32{CR}{LF}

C.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.