ATO CMM 900-3W - Manual (Page 12)

Page 12 of 12
5.2 On-line State:
In Online state, input(s) from the PC is treated as data to be transmitted over the
airwaves, and input(s) from the airwaves is treated as received data from the remote end.
The cellular modem is in online state in one of the two conditions:
•
Cellular modem dials out and a successful connection is established.
•
Cellular modem answers an incoming call and a successful connection is established.
When the cellular modem is in “Online” state. All serial data presented to the radio is
transmitted over the air. DO NOT change communication parameters (e.g. baud rate) in
this mode.
To go back to Command State, Escape Sequence (described below) is required.
5.3 Transitioning Online State
а а Command State:
The sequence of characters to transition from Online State to the Command State is
called the escape sequence.
For cellular modem, the escape sequence is +++.
The timing interval between the ”+” signs must be between 250 msecs and 750 msecs.
When the cellular modem receives a valid escape sequence, the modem will enter
Command State and respond with OK.