Comtech EF Data SMS-301 - Manual (Page 85)

SMS-301 Redundancy Switch Remote Control Operation
Rev. 3 A-3
A.2.2 Device Address
The device address is the address of the 1:1 switch which is designated to receive a
transmitted command, or which is responding to a command.
Valid device addresses are 1 to 3 characters long, and in the range of 1 to 255. Address 0
is reserved as a global address which simultaneously addresses all devices on a given
communications link. Devices do not acknowledge global commands.
Each 1:1 switch which is connected to a common remote communications link must be
assigned its own unique address. Addresses are software selectable at the modem, and
must be in the range of 1 to 255.
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 1:1 switch 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/?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.)
>add/?ER6_budy'cr''lf']
(Error message indicating that the command sent cannot be carried out because local processing is utilizing the
modem control bus.)