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
5.1Command 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.
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