Comtech EF Data SDM-100A - Manual (Page 155)

SDM-100A Satellite Modem Remote Control Operation
Rev. 0 A–3
A.2.3 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; send 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.
A.2.4 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