Specifications

AC65/AC75 Hardware Interface Description
3.3 Power-Up / Power-Down Scenarios
s
AC65_AC75_HD_v01.002 Page 38 of 117 2006-10-30
Confidential / Released
The maximum temperature ratings are stated in Section 5.2. Refer to Table 7 for the associated URCs.
3.3.4.2 Deferred Shutdown at Extreme Temperature Conditions
In the following cases, shutdown will be deferred if a critical temperature limit is exceeded:
• while an emergency call is in progress
• during a two minute guard period after power-up. This guard period has been introduced in order to allow the
user to make an emergency call. The start of an emergency call extends the guard period until the end of the
call. Any other network activity may be terminated by shutdown upon expiry of the guard time. The guard
period starts again when the module registers to the GSM network the first time after power-up.
If the temperature is still out of range after the guard period expires or the call ends, the module switches off
immediately (without another alert message).
CAUTION! Automatic shutdown is a safety feature intended to prevent damage to the module. Extended usage
of the deferred shutdown functionality may result in damage to the module, and possibly other severe conse-
quences.
3.3.4.3 Monitoring the Board Temperature of AC65/AC75
The AT^SCTM command can also be used to check the present status of the board. Depending on the selected
mode, the read command returns the current board temperature in degrees Celsius or only a value that indicates
whether the board is within the safe or critical temperature range. See [1] for further instructions.
Table 7: Temperature dependent behavior
Sending temperature alert (2min after AC65/AC75 start-up, otherwise only if URC presentation enabled)
^SCTM_A: 1 Caution: Battery close to overtemperature limit.
^SCTM_B: 1 Caution: Bboard close to overtemperature limit.
^SCTM_A: -1 Caution: Battery close to undertemperature limit.
^SCTM_B: -1 Caution: Board close to undertemperature 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: Battery equal or beyond overtemperature limit. AC65/AC75 switches off.
^SCTM_B: 2 Alert: Board equal or beyond overtemperature limit. AC65/AC75 switches off.
^SCTM_A: -2 Alert: Battery equal or below undertemperature limit. AC65/AC75 switches off.
^SCTM_B: -2 Alert: Board equal or below undertemperature limit. AC65/AC75 switches off.