Mocomtech CIM-550 - Manual (Page 83)

CiM-550 IP Enabled Satellite Modem Rev. 2
Serial Remote Control CD/CIM550.IOM
57
5.5 P ACKET S TRUCTURE
Controller-to-target:
Start of
Packet Target
Address Address
De-limiter
Instructio
n
Code
Code
Qualifier Optional
Arguments
End of
Packet
<
ASCII
code 60
(1
character) (4
characters)
/
ASCII code
47
(1
character) (3
characters)
= or ?
ASCII code
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
De-limiter
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 code 61,
63, 33 or 42
(1 character)
(From 0 to n
characters) Carriage
Return, Line
Feed
ASCII code
13,10
(2 characters)
Example: >0654/RSW=32{CR}{LF}
Each of the components of the packet is explained below.
5.5.1 S TART O F P ACKET
Controller to Target: This is the character ‘<’ (ASCII code 61)
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.
5.5.2 A DDRESS
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
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.