CRS-300 1:10 Redundancy Switch Revision 16
Remote Control MN/CRS300.IOM
C–3

o To a local BUC or transceiver connected to a local modem;

o To a distant end BUC or transceiver through the distant end modem.

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: <0000/RSH=30[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: >0000/BBU=107[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.

C.5.2 T arget Address

While up to 9,999 devices can be uniquely addressed, connection to the CRS-300 imposes some

basic limitations:

• In EIA-232 applications, the Switch address is fixed at 0000.
• In EIA-485 applications, the Switch may be set to an address of 1000, 3000, 5000 or

7000. This allows up to four Switches to be connected on the same bus.

• The 11 modems that may be connected to the Switch may be accessed for remote monitor

& control through the Switch via virtual addresses. The details of this addressing scheme is

shown in Appendix B. ADDRESSING SCHEME INFORMATION. Valid remote

commands and queries that can be sent to the modems via the Switch depend upon the