Siemens Java TC65 - Manual (Page 25)

TC65 JAVA User's Guide
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TC65 JAVA User's Guide_V05 Page 25 of 90 26.09.2005
5.2 Power Saving
The module supports several power saving modes which can be configured by the AT
command at+cfun [3]. 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
efficiency 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 while 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
constant for at least 2.12s to detect any changes. For further details refer to [4].
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).
5.3 Charging
Please refer to [3] and [4] for general information about charging. Charging can be monitored
by the running Java application. The JVM is active in Charge mode and in Charge-Only
mode if autostart is activated. Only a limited number of AT commands are available when the
module is in Charge-Only mode. A Java application must be able to handle the Charge-Only
mode and reset the module to reinstate the normal mode. See [4] for information about the
Charge-Only mode.
The Charge-Only mode is indicated by URC “^SYSSTART CHARGE-ONLY MODE”.
Note: When a Java application is started in Charge-Only mode only AT Command APIs
without CSD are available. The mode-indicating URC is created after issuing the very first AT
command on any opened channel. To read the URC it is necessary to register a listener (see
[5]) on this AT command API instance before passing the first AT command.