11
The RC3000A-E provides an UART (universal asynchronous serial transmission)
port. It consists of a flexible 7-wire serial interface. The module is as the DCE
(Data Communication Equipment) and the client PC is as the DTE (Data Terminal
Equipment). AT commands are entered and serial communication is performed
through UART interface.
The application circuit is in the following figures.
Full modem
Null modem
If UART port is used in Null Modem, the pin “RI” can be used as an interrupt signal
to HOST. Normally it will keep high logic level until certain condition such as
receiving SMS, voice call (CSD, video) or URC reporting, then “RI” will change to
MODULE(DCE)
Serial port
TXD
RXD
RTS
CTS
DTR
DCD
RI
MODULE(DCE)
Serial port
TXD
RXD
RTS
CTS
DTR
DCD
RI
R
R
R
R
R
R
R
MODULE(DCE)
Serial port
TXD
RXD
RTS
CTS
DTR
DCD
RI
MODULE(DCE)
Serial port
TXD
RXD
RTS
CTS
DTR
DCD
RING
GPIO
R
R
Wake up host
X
X
X
X
