ATO CMM 900-3W - Manual (Page 9)

Page 9 of 9
Step 1: Enter ATDT XXXX <CR> XXXX is the phone number of the modem you
are calling. After approximately 30 seconds, the Cellular Modem responds
with CONNECT message.
Step 2: Type “ Hello”
The party you called should see the message on their terminal screen.
Step 3: Ask the called party to type a message and you should see that message on
your terminal screen.
Step 4: Enter the Escape sequence +++. The modem responds OK.
Step 5: Enter ATH0<CR>
The Cellular Modem responds “No Carrier “ indicating that the connection is
terminated.
Step 6: Ask the called party to dial your MIN number. Cellular Modem responds
with CONNECT message after approximately 30 seconds.
Step 7: Repeat steps 2 to 5.
5. THEORY OF OPERATION
The cellular modem is always in one of the following two states:
•
Command state, or
•
Online state
5.1 Command State:
The Cellular Modem assumes the Command state when it is turned ON. In this state, you
can configure the unit for a particular application. In the Command State, all inputs from
the PC are treated as commands.
5.1.1 Command guidelines
Command line is a string of characters sent from the DTE (example - PC) when the unit
is in the Command state. All commands must conform to the following guidelines.
•
Command lines must have a prefix , a body and a terminator
•
Command lines must begin with a character sequence AT
•
Command Lines must end with Carriage return (CR)
•
Either all upper case or all lower case characters must be used
Each command must be entered separately. Command buffer has 40 characters.