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Command/response, A.1.3 c – Comtech EF Data SDM-2020 User Manual

Page 220

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SDM-2020 Satellite Modulator

Revision 7

Remote Control Operation MN/SDM2020M.IOM

A.1.3

C

OMMAND

/R

ESPONSE

The command/response portion of the message contains a variable-length character
sequence, which conveys command and response data.

If a satellite modulator 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. These acknowledgment messages are:

>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.

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