Siemens XT65 - Manual (Page 37)

Java User’s Guide
5.2 Remote SIM Access
49
s
wm_java_usersguide_v12 Page 37 of 123 2008-02-25
Confidential / Released
5.2 Remote SIM Access
While Remote SIM Access (RSA) is normally closely coupled with the GSM 07.10 multiplexer
there are some things to keep in mind when using it with Java.
•
Java must not be started when RSA and/or the GSM 07.10 multiplexer is activated.
• When activating the RSA mode (AT^SRSA) via a Java AT Command channel while Java
is running the parameter of the AT^SRSA command is ignored and RSA is
activated on the channel where the command was issued. The Input- and Outputstream
can then be used to transfer RSA protocol data.
5.3 Power Saving
The module supports several power saving modes which can be configured by the AT com-
mand AT+CFUN
[1] . Power saving affects the Java application in two ways. First, it limits
access to the serial interface (RS-232-API) and the GPIO pins. Second, power saving effi-
ciency is directly influenced by the way a Java application is programmed.
Java hardware access limitations:
•
In NON-CYCLIC SLEEP mode (cfun=0) the serial interface cannot be accessed. Toggling
RTS does end NON-CYCLIC SLEEP mode. In CYCLIC SLEEP mode (CFUN=7 or 9) the
serial interface can be used with hardware flow control (CTS/RTS).
• In all SLEEP modes the GPIO polling frequency is reduced so that only signal changes
which are less than 0.2Hz can be detected properly. Furthermore, the signal must be con-
stant for at least 2.7s to detect any changes. For further details see AT^SCPOL in
[1] or
refer to [2] .
Java power saving efficiency:
•
As long as any Java thread is active, power consumption cannot be reduced, regardless
whether any SLEEP mode has been activated or not. A Java application designed to be
power efficient should not have any unnecessarily active threads (e.g. no busy loops).
Threads waiting in a blocking method (e.g. read) do not hinder power saving.
• When using networking functionality close all connectors and hang-up the bearer manually
(using ATH for circuit switched connections or AT+CGATT=0 in case of GPRS) every time
you intend to reduce power consumption. Disable the network idle timeout (=0).
When going to low power mode there always might be a transition time of around 10s till low
power consumption state is reached.