Cinterion EGS5, Hardware Interface Description

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EGS5 Hardware Interface Description
3.3 Power Up / Power Down Scenarios
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EGS5_HD_v02.004 Page 38 of 123 2012-02-09
Confidential / Released
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3.3.4 Automatic Shutdown
Automatic shutdown takes effect if:
•
the EGS5 board is exceeding the critical limits of overtemperature or undertemperature
• the battery is exceeding the critical limits of overtemperature or undertemperature
• undervoltage or overvoltage is detected
See Charge-only mode described in Section 3.5.6 for exceptions.
The automatic shutdown procedure is equivalent to the Power-down initiated with the
AT^SMSO command, i.e. EGS5 logs off from the network and the software enters a secure
state avoiding loss of data.
Alert messages transmitted before the device switches off are implemented as Unsolicited Re-
sult Codes (URCs). The presentation of these URCs can be enabled or disabled with the two
AT commands AT^SBC and AT^SCTM. The URC presentation mode varies with the condition,
please see
Section 3.3.4.1 to Section 3.3.4.3 for details. For further instructions on AT com-
mands refer to [1] .
3.3.4.1 Thermal Shutdown
The board temperature is constantly monitored by an internal NTC resistor located on the PCB.
The NTC that detects the battery temperature must be part of the battery pack circuit as de-
scribed in
Section 3.5.3 The values detected by either NTC resistor are measured directly on
the board or the battery and therefore, are not fully identical with the ambient temperature.
Each time the board or battery temperature goes out of range or back to normal, EGS5 instantly
displays an alert (if enabled).
•
URCs indicating the level "1" or "-1" allow the user to take appropriate precautions, such as
protecting the module from exposure to extreme conditions. The presentation of the URCs
depends on the settings selected with the AT^SCTM write command:
AT^SCTM=1: Presentation of URCs is always enabled.
AT^SCTM=0 (default): Presentation of URCs is enabled during the 2 minute guard period
after start-up of EGS5. After expiry of the 2 minute guard period, the presentation will be
disabled, i.e. no URCs with alert levels "1" or ''-1" will be generated.
• URCs indicating the level "2" or "-2" are instantly followed by an orderly shutdown, except
in cases described in
Section 3.3.4.2 . The presentation of these URCs is always enabled,
i.e. they will be output even though the factory setting AT^SCTM=0 was never changed.
The maximum temperature ratings are stated in Section 5.2 . Refer to Table 9 for the associated
URCs.