Comtech EF Data SMS-758 - Manual (Page 124)

Remote Control Operation SMS-758 Modem Protection Switch
A–2 MN/SMS758 Rev. 3
Messages on the remote link fall into the categories of commands and responses.
Commands are messages which are transmitted to a satellite modem switch, while
responses are messages returned by a satellite modem switch in response to a command.
The general message structure is as follows:
•
Start Character
•
Device Address
•
Command/Response
•
End of Message Character
A.2.1 Start Character
A single character precedes all messages transmitted on the remote link. This character
flags the start of a message. This character is:
•
“<” for commands
•
“>” for responses
A.2.2 Device Address
The device address is the address of the one 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 switch which is connected to a common remote communications link must be
assigned its own unique address. Addresses are hardware (dipswitch) selectable at the
modem switch, and must be in the range of 1 to 255.
Note: “add” is used to indicate a valid 1 to 3 character device address in the range
between 1 and 255.