User's Manual
Table Of Contents
- Contents
- Figures
- Tables
- Document history
- Introduction
- Product concept
- GSM application interface
- GSM/GPRS operating modes
- Power supply
- Power up / down scenarios
- Automatic GPRS Multislot Class change
- Charging control of the GSM part
- Power saving
- Summary of state transitions (except SLEEP mode)
- RTC backup for GSM part of XT55/56
- Serial interfaces of the XT55/56 GSM part
- Audio interfaces
- SIM interface
- Control signals
- GPS application interface
- GSM and GPS antenna interfaces
- Electrical, reliability and radio characteristics
- Mechanics
- Reference approval
- Example applications
- List of parts and accessories
XT55/56 Hardware Interface Description
Confidential / Released
s
XT55/56_hd_v02.06a Page 38 of 125 17.12.2004
Table 6: Temperature dependent behavior
Sending temperature alert (15 s after start-up, otherwise only if URC presentation enabled)
^SCTM_A: 1 Caution: T
amb
of battery close to over temperature limit.
^SCTM_B: 1 Caution: T
amb
of board close to over temperature limit.
^SCTM_A: -1 Caution: T
amb
of battery close to under temperature limit.
^SCTM_B: -1 Caution: T
amb
of board close to under temperature limit.
^SCTM_A: 0 Battery back to uncritical temperature range.
^SCTM_B: 0 Board back to uncritical temperature range.
Automatic shutdown (URC appears no matter whether or not presentation was enabled)
^SCTM_A: 2 Alert: T
amb
of battery equal or beyond over temperature limit. XT55/56 switches off.
^SCTM_B: 2 Alert: T
amb
of board equal or beyond over temperature limit. XT55/56 switches off.
^SCTM_A: -2 Alert: T
amb
of battery equal or below under temperature limit. XT55/56 switches off.
^SCTM_B: -2 Alert: T
amb
of board equal or below under temperature limit. XT55/56 switches off.
3.3.3.2 Temperature control during emergency call
If the temperature limit is exceeded while an emergency call is in progress the engine
continues to measure the temperature, but deactivates the shutdown functionality. If the
temperature is still out of range when the call ends, the module switches off immediately
(without another alert message).
3.3.3.3 Undervoltage shutdown if battery NTC is present
In applications where the module’s charging technique is used and an NTC is connected to
the GSM_BATT_TEMP terminal, the software constantly monitors the applied voltage. If the
measured battery voltage is no more sufficient to set up a call the following URC will be
presented:
^SBC: Undervoltage.
The message will be reported, for example, when you attempt to make a call while the
voltage is close to the critical limit and further power loss is caused during the transmit burst.
To remind you that the battery needs to be charged soon, the URC appears several times
before the module switches off.
To enable or disable the URC use the AT^SBC command. The URC will be enabled when
you enter the write command and specify the power consumption of your GSM application.
Step by step instructions are provided in [1].