Ericsson F251m Manual de usuario descargar pdf (Pagina 21)

4. OPERATION

LZT 123 7359 R1B

4. Operation

4.1 Switching On the Modem

There are two ways to switch on the modem, once power is applied.

• either assert TO_IN high for > 0.2s;

• or activate the RS232 control line DTR, high for > 0.2s.

The modem is fully operational after 4 seconds. Logging onto a network

may take longer than this and is outside the control of the modem.

The modem can be configured to start up at the time power is applied

by permanently tying power connector signals TO_IN (pin 4) and VCC

(pin 1) together. In this case DTR must be used to switch the modem on

again after it has been switched off or reset, while power is still applied.

4.2 Switching Off the Modem

There are two ways to switch off the modem as described below:

• either use the appropriate AT command;

• or assert HR_IN high for 1 - 2 seconds. A delay of up to 10s is

experienced as the modem logs off the network.

4.3 Resetting the Modem

A full system reset, independent of the status of the software, may be

applied to the modem as follows:

• assert HR_IN high for > 3.5s.

4.4 Operating States/LED

The modem has a green LED, as depicted below, which is used to

indicate various operating states. These states are described in

following table.

LED

1 2 ... 16 17 18 19 20 21 22 23 24 25 26 ... 29 30

Sin comentarios

Ericsson F251m Manual de usuario Pagina 21