Cep Terminals GSM/GPRS TERMINAL CT63 JAVA 6203 User Manual

5.9 System Out

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wm_java_usersguide_v19

Page 32 of 109

2012-01-27

Confidential / Released

There is a small set of special Java AT commands:
•

AT^SJRA, start a Java application

•

AT^SJNET, configuration of Java networking connections

•

AT^SJOTAP, start and configuration of over the air provisioning

•

AT^SJSEC, security configuration 

Refer to the AT command Set 

Under Java, the AutoExec function’s AT command execution has some restrictions (see 

 for 

details on the AutoExec function). If an AT command is executed, neither URC nor command 
response are indicated to the Java application. Therefore, it is recommended to use the Auto-
Exec function under Java only with commands that shut down the module, e.g., with 
AT+CFUN=0,1, as a watch dog. Any other AT command execution should be implemented with 
Java means and the ATCommand class.

Any output printed to the System.out stream by a Java application can be redirected to one of 
the serial interfaces, a file, a "NULL" device (i.e. the output will be discarded) or a UDP socket 
for using the debugger from an IDE. The configuration can be done at any time using the AT 
command AT^SCFG (see 

 for details) and is non-volatile. 

System.out can be written to any of the serial interfaces ASC0, ASC1 or USB. If System.out is 
redirected to one of the interfaces used for the Java CommConnection, the interface will be 
shared between System.out and the CommConnection. This will result in mixed output, if data 
is written to the CommConnections OutputStream and something is printed via System.out at 
the same time. 

Using System.out and CommConnection on the same serial interface may be done if a device 
connected to the serial port is only transmitting data to the module. It is recommended to en-
sure already in the HW design that output from the module cannot be transferred to a connect-
ed device.

The System.out print can be redirected into log files within the module’s flash file system. The 
output will be written alternatingly into two files which can be concatenated afterwards to have 
a single log file. 

Writing the output to a file will slow down the virtual machine. To reduce the impact of logging 
the output may be written first to a buffer before it is written to the file (buffered mode). The buff-
ered output is written either if the buffer is filled or after 200 ms. If the buffer is not used (secure 
mode) the output is written directly to the file. Because excessive writing to the module’s flash 
file system decreases the life time of the flash memory, we recommend using the System.out 
to file redirection only during development phases.