Terrasat IBUC 3, Operation Manual

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M&C Interfaces
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5-7
Engineered to Endure
ASCII Mode Response Format
• Start of Packet: > (ASCII code 62; 1 character)
• Target Address: XXXX (4 characters)
• Address De-limiter: / (ASCII code 47; 1 character)
• Variable Length Data: (n characters)
• End of Packet:
Carriage Return (ASCII code 13; 1 character)
Line Feed (ASCII code 10; 1 character)
Example:
>0001/(Variable Length Data) [CR][LF]
Commands and values available in ASCII mode are provided in the command set in
Appendix F .
Legacy Binary Mode
Legacy binary mode is the default RS485 setting for the IBUC. In Legacy Binary
Mode, you will need to use a separate network management program.
For the RS485 interface, the packet is encapsulated inside a data link layer packet
which has an address “header” byte and a checksum “trailer” byte. Table 5.5 contains
the packet format.
Each transmitted command data packet consists of the seven bytes shown in Table 5.6 .
Where:
• Byte 1 contains the IBUC address that is being required. The IBUC will accept a
command only if the first byte contains the appropriate address.
• Byte 2 contains the major command. See Appendix E for possible commands.
Table 5.5
Legacy Binary Mode Packet Format
Byte Description
1
RS485 destination address of command. For responses, responder address is
shifted left by 4 bits.
2~6 Command or response packet data
7 CHECKSUM: the checksum should be equal to the Data Packet Byte checksum
Table 5.6
Data Packet Byte Configuration
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
IBUC
3
Address
Command Data Byte 1 Data Byte 2 Data Byte 3 Data Byte 4 Checksum