Siemens M1 - Manual (Page 20)

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GSM M1 Module, English: A24859-N4000-A100-1-7677 gsm-m1-e.fm
Technical reference section
6.3.96
Once you have read through this section, you will be able to use your GSM module to-
gether with your communication program to perform the following functions:
• Interrupt a connection using the escape command.
• Go off-hook.
• Set up a connection by manually dialing the telephone number.
• Store a telephone number.
• Dial a stored telephone number.
• Answer a call.
• Switch to auto-answer.
The GSM module operates in two different modes:
• Command mode
• Transparent mode
When you switch on your system, the GSM module is in command mode and is ready
to receive and execute your commands. All characters that the GSM module receives
via the COM interface in this mode are interpreted as commands and, if a phone con-
nection is present, are not transferred to the distant station.
In transparent mode, the GSM module transfers every character sent and received via
the COM interface just as it is.
Before attempting to dial your first call, you must know how to interrupt or disconnect
a call at any time. This involves the following two steps:
• Enter

to switch to command mode.
• Disconnect the call by entering ATH.
Example:
Situation: The GSM module is operating in transparent mode, i.e. a connection is set
up to a distant station.
Change to command mode:
• Do not press any key for at least one second.
• Press the

key three times in rapid succession (within one second).
• Do not press another key for at least one second.
The GSM module switches to command mode, i.e. it interrupts the flow of data and
Setting up and clearing down connections
Operating modes
Command mode
Transparent mode
Escape command