Siemens XT65 - Manual (Page 118)

Java User’s Guide
13.1 Using the AT Command API
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13.1.3 ATCommandListener Interface
The ATCommandListener interface implements callback functions for:
•
URCs
• Changes of the serial interface signals RING, DCD and DSR
• Opening and closing of data connections
The user must create an implementation class for ATCommandListener to receive AT events.
The ATEvent method of this class must contain the processing code for the different AT-Events
(URCs). The RINGChanged, DCDChanged, DSRChanged and CONNChanged methods
should contain the processing code for possible state changes. This code shall leave the lis-
tener context as soon as possible (i.e. running a new thread). While the callback method does
not return it cannot be called again if changes occur.
The CONNChanged method indicates the start and the end of data connections. During a data
connection it is possible to transfer data with the I/O stream methods (see
Section 13.1.1.3 ).
Some data services (i.e. FTP) transfer the data so quickly, that the CONNChanged start and
close events are received even parallel to the response of the AT command which originated
the data connection. The user’s application must realize, that the data connection had taken
place and read the data with the I/O stream read methods afterwards.
13.1.3.1 ATEvents
An ATEvent or a URC is a report message sent from the module to the application. An unso-
licited result code is either delivered automatically when an event occurs or as a result of a
query the module previously received. However, a URC is not issued as a direct response to
an executed AT command. Some URCs must be activated with an AT command.
Typical URCs may be information about incoming calls, a received SM, temperature changes,
the status of the battery, etc. A summary of URCs is listed in
[1] .