Specifications

Chapter 11 – SocketModem HSDPA
Multi-Tech Systems, Inc. Universal Socket Hardware Guide for Developers (S000342I) 150
Turn off the SocketModem Using AT Command
The best and safest approach to powering down is to issue the AT^SMSO command. This procedure lets the SocketModem
log off from the network and allows the software to enter into a secure state and safe data before disconnecting the power
supply. The mode is referred to as Power-down mode. In this mode, only the RTC stays active.
After sending AT^SMSO do not enter any other AT commands. There is one way to verify that the SocketModem turns off:
Wait for the ”OK” – response. It indicates that data has been stored non-volatile and that the SocketModem turns after
about one second.
Important Note: The SocketModem requires a reset to become active again.
Automatic Shutdown
Automatic shutdown takes effect if:
• The modem exceeds the critical limits of overtemperature or undertemperature.
The board temperature is constantly monitored by an internal NTC resistor. The values detected by the NTC resistor
are measured directly on the board and are therefore not fully identical with the ambient temperature.
Each time the board temperature goes out of range or back to normal, the modem instantly displays an alert (if
enabled).
 URCs indicating the level "1" or "-1" allow the user to take appropriate precautions, such as protecting the
SocketModem 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 for 15 seconds time after startup. After 15
seconds operation, the presentation will be disabled, i.e. no alert messages can be generated.
 URCs indicating the level "2" or "-2" are instantly followed by an orderly shutdown, except in cases of
temperature control during an emergency call (see paragraph below). 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.
Temperature-Dependent Alerts
Sending temperature alert (15s after start-up; otherwise, only if URC presentation enabled)
^SCTM_B: 1 Caution: SocketModem close to ove
r
-temperature limit.
^SCTM_B: -1 Caution: SocketModem close to unde
r
-temperature limit.
^SCTM_B: 0 SocketModem back to uncritical temperature range.
Automatic shutdown (URC appears no matter whether or not presentation was enabled)
^SCTM_B: 2 Alert: SocketModem is above ove
r
-temperature limit and switches off.
^SCTM_B: -2 Alert: SocketModem is below unde
r
-temperature limit and switches off.
Notes:
• The MTSMC-H will not transmit temperature URC alerts.
• The URCs will not display in data mode.
Temperature Control during an 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 SocketModem
switches off immediately (without another alert message).
Power Saving
The modem is able to reduce its functionality to a minimum (during the so-called SLEEP mode) in order to minimize its current
consumption. The following sections explain the SocketModem’s network dependant power saving behavior.
The implementation of the USB host interface also influences the SocketModem’s power saving behavior and therefore its
current consumption. During normal WCDMA operation; i.e., the modem is connected to a WCDMA network, the duration of a
power-saving period varies. It may be calculated using the following formula:
t = 2
DRX value
* 10 ms (WCDMA frame duration).