Here is the used equipment :
* RaspBerry Pi (B) 512Mo
* Modem PacComm TINY-2
* Transceiver Alcatel ATR 2680
* USB<-->TTL adapter chipset CP210
To avoid using a MAX232 interface to convert RS232 to TTL, I used TTL connector on the PacComm TINY-2.
Cablig is as follow :
PIN……………….USB Adapter
1 ————-> TXD
5 ————-> RXD
6 ————-> GROUND