Siemens TC65 Specifications download pdf (Page 48)

TC65 Hardware Interface Description

Confidential / Released

TC65_HD_V02.000 Page 48 of 120 08.06.2006

3.6 Power Saving

Intended for power saving, SLEEP mode reduces the functionality of the TC65 to a minimum

and thus minimizes the current consumption. Settings can be made using the AT+CFUN

command. For details see

[1]. SLEEP mode falls in two categories:

• NON-CYCLIC SLEEP mode: AT+CFUN = 0

• CYCLIC SLEEP modes, AT+CFUN = 7 or 9.

The functionality level AT+CFUN=1 is where power saving is switched off. This is the default

after startup.

NON-CYCLIC SLEEP mode permanently blocks the serial interface. The benefit of the

CYCLIC SLEEP mode is that the serial interface remains accessible and that, in intermittent

wake-up periods, characters can be sent or received without terminating the selected mode.

This allows the TC65 to wake up for the duration of an event and, afterwards, to resume

power saving. Please refer to

[1] for a summary of all SLEEP modes and the different ways

of waking up the module.

For CYCLIC SLEEP mode both the TC65 and the application must be configured to use

hardware flow control. This is necessary since the CTSx signal is set/reset every 0.9-2.7

seconds in order to indicate to the application when the UART is active. Please refer to

[1]

for details on how to configure hardware flow control for the TC65.

Note: Although not explicitly stated, all explanations given in this chapter refer equally to

ASC0 and ASC1, and accordingly to CTS0 and CTS1 or RTS0 and RTS1.

3.6.1 Network Dependency of SLEEP Modes

The power saving possibilities of SLEEP modes depend on the network the module is

registered in. The paging timing cycle varies with the base station. The duration of a paging

interval can be calculated from the following formula:

t = 4.615 ms (TDMA frame duration) * 51 (number of frames) * DRX value.

DRX (Discontinuous Reception) is a value from 2 to 9, resulting in paging intervals from

0.47-2.12 seconds. The DRX value of the base station is assigned by the network operator.

In the pauses between listening to paging messages, the module resumes power saving, as

shown in

Figure 10.

Figure 10: Power saving and paging

The varying pauses explain the different potential for power saving. The longer the pause

the less power is consumed.

0.47-2.12 s

0.47-2.12 s 0.47-2.12 s

Paging

Power Saving

1 2 ... 43 44 45 46 47 48 49 50 51 52 53 ... 119 120

Comments to this Manuals

No comments

Siemens TC65 Specifications Page 48

Comments to this Manuals

Related products and manuals for Networking Siemens TC65