Comtech EF Data SDM-650B - Manual (Page 314)

Trojan Interface SDM-650B Satellite Modem
G–18 Rev. 5
G.6.2 Command/Response
The command/response portion of the message contains a variable length character
sequence which conveys command and response data.
If a satellite modem receives a message addressed to it which does not match the established
protocol or cannot be implemented, a negative acknowledgment message is sent in
response. This message is:
• >add/?ER1_PARITY ERROR”cr””lf”]
(Error message for received parity errors.)
• >add/?ER2_INVALID PARAMETER”cr””lf”]
(Error message for a recognized command which cannot be implemented or has parameters which
are out of range.)
• >add/?ER3_UNRECOGNIZABLE COMMAND”cr””lf”]
(Error message for unrecognizable command or bad command syntax.)
• >add/?ER4_MODEM IN LOCAL MODE”cr””lf”]
(Modem in local error; use the REM command to go to remote mode.)
• >add/?ER5_HARD CODED PARAMETER”cr””lf”]
(Error message indicating that the parameter is hardware dependent and may not be changed
remotely.)
Note: “add” is used to indicate a valid 1 to 3 character device address in the range
between 1 and 255.
G.6.3 End Character
Each message is ended with a single character which signals the end of the message:
• “cr” Carriage return character for commands
• “]” End bracket for responses