> 2.2.4 | Initialization of serial interface

> This section comprises the subsections Description, Used AT Commands, Flow Chart, Hints and Example. To move to these subsections please use the Navigation Frame or the appropriate buttons on the toolbar.

> 2.2.4.1 | Description

> For many applications it is crucial to make settings on the serial interface to ensure reliable operation. We recommend using the following AT commands to adjust these settings:
> With AT+IPR the baud rate between the application and module can be chosen. It may, depending on the application, be wise to use a higher baud rate when transmitting large amounts of data.
> AT&C, AT&D and AT&S are provided to configure the behavior of the status lines (DCD, DTR, DSR). Depending on the configuration made the status of the lines will indicate different events such as: Presence of a data carrier, data mode/command mode etc.

> 2.2.4.2 | Used AT commands

> Command | Explanation
> AT&C | Set circuit Data Carrier Detect (DCD) function mode
> AT&D | Set circuit Data Terminal Ready (DTR) function mode
> AT&S | Set circuit Data Set Ready (DSR) function mode
> AT+IPR | Set fixed local rate

> For further details about the commands see [2].

> 2.2.4.3 | Flow Chart

> Figure 8: Initialization of serial interface

> 2.2.4.4 | Hints

> • | Autobauding is not compatible with Multiplexer mode.

> 2.2.4.5 | Example

> ***************************************
> Comment: Initialization of serial interface
> ***************************************
> ***************************************
> Comment: Query bit rate
> ***************************************
> Subscr 1 Send: AT+IPR?
> Subscr 1 Receive: AT+IPR?
> Subscr 1 Receive: +IPR: 0
> Subscr 1 Receive:
> Subscr 1 Receive: OK
> ***************************************
> Comment: Set bit rate per second (baud) AT+IPR=0 (Autobauding)
> ***************************************
> Subscr 1 Send: AT+IPR=0
> Subscr 1 Receive: AT+IPR=0
> Subscr 1 Receive: OK
> ***************************************
> Comment: Set circuit (DCD) function mode (AT&C0 default, AT&C1 presence of data carrier only))
> ***************************************
> Subscr 1 Send: AT&C0
> Subscr 1 Receive: AT&C0
> Subscr 1 Receive: OK
> ***************************************
> Comment: Set circuit (DTR) function mode
> ***************************************
> Subscr 1 Send: AT&D2
> Subscr 1 Receive: AT&D2
> Subscr 1 Receive: OK
> ***************************************
> Comment: Set circuit (DSR) function mode
> ***************************************
> Subscr 1 Send: AT&S0
> Subscr 1 Receive: AT&S0
> Subscr 1 Receive: OK