Operation
RFI-9256 Radio Modem User Manual
Page 34 of 109
5.3.3 Hayes Dial-up Protocol
Hayes dial-up networks provide connection mechanism that emulates a PSTN modem’s dialling mechanism.
This is a more powerful method of operating than using point-to-point or point-to-multipoint broadcast
networks, as it allows dedicated communication between a master and one of many slaves.
CONNECTION MANAGEMENT
DIALLING
The AT commands may be used to initiate dialling of a remote radio. The
ATD
command is use to establish a
connection. The form of the
ATD
command is:
ATD<address><extension>
Where
<address>
is the address of the radio that is being dialled, and
<extension>
is the serial port or
internal extension port that is being dialled. The available extension numbers are shown in Table 10.
NOTE
: When dialling radio modems with a single digit unit address, a leading zero must be added (eg 01
for unit with address 1).
Extension
Name
Description
00
Main Port
Establishes a connection between the current serial port and the main port
on the remote unit,
01
Auxiliary Port
Establishes a connection between the current serial port and the auxiliary
port on the remote unit,
91
Virtual Hayes
Establishes a connection between the current serial port and the Hayes
command interface running on the remote unit.
92
Remote Menu
Establishes a connection between the current serial port and the menu of
the remote unit. When connection to a menu system remotely, the radio
configuration menu (see Appendix B.1 on page 69) will not be available.
This is done to prevent configuration changes that could sever the
connection to the remote radio.
93
Remote Logger
Establishes a connection between the current serial port and the logs of
the remote unit.
99
Loop-back
Establishes a connection that loops back all data that is transmitted to the
remote unit.
Table 10: Hayes dial-up extension numbers
The
<address>
and
<extension>
sections of the
ATD
command can include any number of colons,
dashes, or spaces as these will be stripped out of the string by the radio.
If the radio receives a character on the serial port while dialling is in progress it will immediately terminate
the connection attempt and send a
NO CARRIER
response message.
Main -> Protocol
