Rev 1.0
1/27/14
21
21
Reference Guide
Interfaces
3.1.1.2.
ON/OFF Pin
The modem has an external ON/OFF pin which is used to turn the device ON or OFF.
The following table describes the operation of this pin.
Table 6.
ON/OFF Pin Operation
Condition
State
Power Supply
Operation
1
Open
When 4.75V to 32V supply is
applied.
The modem is turned ON.
2
Pulled to GND
When 4.75V to 32V supply is
applied.
The modem remains OFF.
3
Left open when turning
ON the modem, then
pulled to GND
4.75V to 32V supply is initially
applied.
The modem remains ON and will
remain ON until
AT+CPOF
is sent to
turn the device OFF.
To enable the low power mode, the user may simply pull the ON/OFF pin to GND
and send
AT+CPOF
to the modem using a communication software such as a
HyperTerminal.
Table 7.
ON/OFF Pin Description
Pin #
Signal
I/O
I/O Voltage
Description
8
ON/OFF
I
4V
Pin to turn the modem ON/OFF.
Refer to the power consumption tables in section 6 Power Consumption for the
power consumption values when the modem is in Alarm mode (Low Power mode).
3.1.2.
Serial Interface
A SUB-D 15-pin connector is available as a serial interface to directly communicate
with the modem. This serial interface is used for:
•
RS232 serial link connection
•
Audio lines connection (microphone and speaker)
•
RESET signal connection
Figure 14. 15-Pin Serial Connector