L
OW
C
OST
GSM M
ODEM
•
•
Pin TxD @ application sends data to TxD of TMAS GSM/GPRS Terminal
Pin RxD @ application receives data from RxD of TMAS GSM/GPRS Terminal
The RS-232 interface is implemented as a serial asynchronous transmitter and receiver conforming to ITU-T
V.24 Interchange Circuits DCE. It is configured for 8 data bits, no parity and 1 stop bit, and can be operated at
bit rates from 300bps to 115Kbps. Autobauding supports bit rates from 4.8Kbps to 115Kbps. Hardware
handshake using the /RTS and /CTS signals and XON/XOFF software flow control are supported.
In addition, the modem control signals /DTR, /DSR, /DCD and /RING are available. The modem control signal
RING (Ring Indication) can be used to indicate to the cellular device application, that a call or Unsolicited Result
Code (URC) is received. There are different modes of operation, which can be set with AT commands.
2.3 SIM Interface
The SIM interface is intended for 3V SIM cards in accordance with GSM 11.12 Phase 2. The card holder is a 5
wire interface according to GSM 11.11. A sixth pin has been added to detect whether or not a SIM card is
inserted.
Removing and inserting the SIM card during operation requires the software to be reinitialized. Therefore, after
reinserting the SIM card it is necessary to restart the terminal.
Note:
•
•
No guarantee can be given, nor nay liability accepted, if loss of data is encountered after removing the
SIM card during operation.
No guarantee can be given for properly initializing any SIM card that the user inserts after having
removed a SIM card during operation. In this case, the application must restart the terminal.
2.4 Radio Interface
An internal RF cable is connected from the antenna reference point (antenna connector type GSC from Murata)
to the SMA (female) connector. To attach the antenna to the TMAS GSM/GPRS Terminal, turn smoothly and
slowly to the SMA (male) connector of antenna at clockwise direction.
DS-GSMT35I-2
Oct ’07
www.rfsolutions.co.uk
©2007
REG No 277 4001, ENGLAND.
Page 5
RFSOLUTIONS [ RFSOLUTIONS.LTD ]
