Sony Ericsson Mobile Communications Inc. TR-505-A2 Manuale Utente

DM15/25 Integrator’s Manual

20 OF 38

The serial channels are used as asynchronous communication links between the application system
and the module. The following table shows the serial data channels related signals:

19

DCD

Data Carrier Detect

O

21

CTS

Clear To Send

O

22

DTR

Data Terminal Ready

I

23

TD

Serial Data To Module (DTMS)

I

24

RTS

Request To Send

I

26

RD

Serial Data From Module (DFMS)

O

All the serial-channel-related signals have the same electrical characteristics. In the following table
you can see some of these characteristics.

The common CMOS electrical specifications defined in Section 4.1.2 General Electrical and
Logical Characteristics are valid for all these signals.

The standard character format is 1 start bit, 8 data bits, non-parity and 1 stop bit. In all, there are 10
bits per character.

That the signal levels do not match the standard RS232 (V.28).

The module provides two general purpose binary inputs and two general purpose binary outputs on
the system connector.

The AT*EGPI command described in section, allows an application to query the states of the two
general purpose binary inputs.

The AT*EGPO command described in section, allows an application to query or set the states of the
two general purpose binary output inputs.