insys icom GSM small 2.0 Manual page 58

Functions
11.12.3.3 Cyclic Sleep Modes
There are several cyclic sleep modes. All these sleep modes have in common that
they poll the serial interface cyclically to use AT commands without exiting the
sleep mode.
The application as well as the INSYS GSM small 2.0 should use hardware hand-
shake for each cyclic sleep mode, because the INSYS GSM small 2.0 signals that it
can accept AT commands at the moment (polling) by enabling or disabling the CTS
control line.
The polling cycle of the serial interface is coupled with the so-called paging re-
quests of the INSYS GSM small 2.0 to the GSM base station and is between 0.47
and 2.12 seconds.
The CTS line becomes active for 4.6 ms with each polling; further 4.6 ms activity of
the serial interface of the INSYS GSM small 2.0 follow (ready to receive). If the start
bit of a character is detected on the serial interface within these 9.2 ms, CTS re-
mains active and the character will be received. The serial interface remains active
following a received character for:
- 2 seconds with AT+CFUN=5 or AT+CFUN=7
- 10 seconds with AT+CFUN=6 or AT+CFUN=8
CTS will also be enabled if the INSYS GSM small 2.0 sends characters to the appli-
cation within the scope of unsolicited result codes.
CTS is inactive in the pauses between the paging requests and, thus, the serial in-
terface.
In the settings AT+CFUN=5 and AT+CFUN=6, the sleep mode will be left permanently
following an SMS or a Connect (data connection); the INSYS GSM small 2.0 is op-
erated in normal mode again (AT+CFUN=1).
In the settings AT+CFUN=7 and AT+CFUN=8, the sleep mode is entered again follow-
ing an SMS or a Connect (data connection).
Configuration with HSComm
A configuration of this function using the HSComm software is not pos-
sible.
Configuration with AT commands
In order to enable cyclic sleep mode, use
the command
Replace <n> with the digit for the respec-
tive sleep mode (refer to the description
above and Table 11 on page 59).
58
INSYS GSM small 2.0
AT+CFUN=<n>