Siemens MC45 Manual page 48

MC45 Hardware Interface Description
P R E L I M I N A R Y
RS-232(0)
Includes the data lines /TXD0 and /RXD0, the status lines /RTS0 and /CTS0 and, in addition,
the modem control lines /DTR0, /DSR0, /DCD0 and /RING0.
It is primarily designed for voice, CSD, fax and GPRS services and for controlling the GSM
engine with AT commands. Full Multiplex capability allows the interface to be partitioned into
three virtual channels, yet with CSD and fax services only available on the first logical
channel. Please note that when the RS-232(0) runs in Multiplex mode, the RS-232(1) cannot
be used.
The /DTR0 signal will only be polled once per second from the internal firmware of MC45.
The /RING0 signal serves to indicate incoming calls and other types of URCs (Unsolicited
Result Code).
RS-232(1)
Includes only the data lines /TXD1 and /RXD1 plus /RTS1 and /CTS1 for hardware
handshake. This interface is intended for voice calls, GPRS services and for controlling the
GSM engine with AT commands. It is not suited for CSD call, fax calls and Multiplex mode.
When a PPP connection is in progress, no URCs can be displayed. As a result, an incoming
call or any other type of URC can only be indicated after the PPP connection was
terminated.
Both interfaces are configured for 8 data bits, no parity and 1 stop bit, and can be operated
at bit rates from 300bps to 230kbps. Autobauding is only selectable on RS-232(0) and
supports the following bit rates: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200,
230400 bps. XON/XOFF software flow control can be used on both interfaces.
MC45_HD_01_V00.02a Page 48 of 90 12.08.2002