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Sleep mode activation
Sleep mode can be activated by passing a configuration message to the device which defines sleep and optional
wake time. See PARAMETER REFERENCE (TDM880I SPECIFIC PARAMETERS) on page 22 for Sleep mode
parameter information.
Sleep mode termination
Sleep mode is terminated - either temporarily or permanently - if at least one of the following conditions occur:
Termination time reached
The Sleep mode service periodically checks the current time and date to resolve the possible wake-up condition.
When the specified time is reached, the device is started up into operative mode.
Power switched ON by the end user
Powering the TDM880i can be controlled by bringing high any of the IGS input signals. If the device is powered on
when the Sleep mode is configured, the device will boot up into operative mode and remain in that state for a fixed
time of 10 minutes. If the Sleep Mode configuration is not updated during this period, the Sleep Mode continues
execution as previously configured.
Power failure
When the main power is returned after a power loss, the device will boot up and check the time settings of the
device. If the power loss caused a reset to the Real Time Clock (RTC), the device is powered to a fully operative
mode, and the RTC recovery routine is started. During this mode, the all Sleep mode settings are temporarily
cancelled until the correct time/date are recovered. After the successful retrieval of the correct time, the Sleep mode
functionality continues execution as configured.
Periodic reset
Data terminals can be installed in remote locations or in locations that are hard to access by maintenance
personnel. TDM880i has a built-in mechanism to recover from possible erroneous conditions within a reasonable
period of time. Controlled periodic reset powers the device off and re-starts it within a configurable period in a
managed way.
Countdown timer for the next periodic reset can be read with the following AT-command.
AT+CXWDCT
NMEA output
The TDM880i provides two ways of routing the NMEA output from the GPS module directly to the AT interface. Both
require an AT command for initiation. To enable the GPS, use the following AT command (if the GPS is not enabled
by default using the parameter settings of the TDM880i):
AT+CXGPSC=value
value 1 activates and 0 disables the GPS.
Periodic Output:
The end user may request the device to enter a state where NMEA is queried periodically from the GPS facilities
and routed to the AT channel at a speed of 9600 b/sec. To enable this mode, the end user must use the following
command.
AT+CXGPSPLR=value
values 1-30 equals time in seconds, the value 0 disables periodic output
Direct Timed Output:
In this mode the device routes the 4800 b/sec. NMEA output directly to the AT output for a specified period of time.
In order to turn this mode on, the following AT command must be used.
AT+CXNMEARD=password, value
Note:
Sleep mode cannot be terminated through the AT/OTA interface when the device is in the hibernate
mode. Such termination always requires interfacing the power switching functionality or the main power
itself.
