Operation
RFI-9256 Radio Modem User Manual
Page 35 of 109
If a connection is established then the
CONNECT
response message will be returned.
ANSWERING
The RFI-9256 provides two options for answering dial-up calls:
Auto-answer:
When in auto answer mode and a connection request is made, the RFI-9256 will
output a configurable number of
RING
responses on the destination radio extension, and then
automatically connect. When dialling an extension other then the main or auxiliary port, auto-
answer is used by default.
Manual answer:
When in manual answer mode the RFI-9256 will output a
RING
response on the
destination once per second until the
ATA
command is received at which point the connection is
established. If no
ATA
command is received within the connect timeout the connection is not
established.
Manual answering of dial-up requests only applies to the main and auxiliary ports. The internal extension
numbers for the virtual Hayes, remote menu, remote logger, and loop-back services will always answer
automatically.
ESCAPE SEQUENCE
When there is no communications link established to a remote radio, and AT commands are issued locally
then the radio is in local command state.
When a connection is established to a remote radio, all communications occurs between the DTE’s
connected to the ports on the two radios. This is known as online state. Once a radio enters online state, it
assumes all the data sent to it is to be sent on to the remote radio, so it ignores all AT commands.
Unlike the other commands, there is no AT prefixing the escape sequence, and no carriage return after the
escape sequence. Instead, wait a full second before entering the three characters (default is ‘+’) typed
rapidly, then wait another full second. As soon as the radio returns to local command state, it will respond
with the message
OK
.
This delay period before and after the escape sequence is called the escape sequence guard time. This allows
the radio to distinguish the escape sequence from the normal flow of user information between radios.
The character used for the escape sequence and the amount of guard time is set in the Hayes command
control menu on page 75. They can also be configured using s-register 2 (page 91) and , s-register 12 (page
91) respectively.
When entering local command state, the connection is not disrupted. In order to return back to online state,
the command
ATO
is used.
HANGING UP
The
ATH
command is used to terminate a connection.
After communications has finished enter the escape sequence (+++). The radio responds with an
OK
message. Then execute the
ATH
command and the local radio will respond with
OK
. The remote radio will
output
NO CARRIER
as the communications link is lost.
