Cep Terminals GSM/GPRS TERMINAL CT63 JAVA 6203 用户手册

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Java User’s Guide
12.1 Using the AT Command API
109
wm_java_usersguide_v19
Page 105 of 109
2012-01-27
Confidential / Released
12.1.3
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 
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.
12.1.3.1
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 que-
ry 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