Motorola MVME712AM 用户手册

Support Information

3-18

A16

32

RTS3

REQUEST TO SEND (serial port 3) - RTS is supplied 
by the terminal to the modem when it is required to 
transmit a message. With RTS off, the modem carrier 
remains off. When RTS is turned on, the modem 
immediately turns on the carrier. 

C17

33

DCD3

DATA CARRIER DETECT (serial port 3) - sent by the 
modem to the terminal to indicate that a valid carrier 
is being received. 

A17

34

DTR3

DATA TERMINAL READY (serial port 3) - a signal 
from the terminal to the modem indicating that the 
terminal is ready to send or receive data. 

C18

35

TXD1

TRANSMIT DATA (serial port 1) - data to be 
transmitted is furnished on this line to the modem 
from the terminal. 

A18

36

GND

GROUND 

C19

37

RXD1

RECEIVE DATA (serial port 1) - data that is 
demodulated from the receive line is presented to the 
terminal by the modem. 

A19

38

GND

GROUND 

C20

39

RTS1

REQUEST TO SEND (serial port 1) - RTS is supplied 
by the terminal to the modem when it is required to 
transmit a message. With RTS off, the modem carrier 
remains off. When RTS is turned on, the modem 
immediately turns on the carrier. 

A20,C21

40,41

GND

GROUND 

A21

42

CTS1

CLEAR TO SEND (serial port 1) - CTS is a function 
supplied to the terminal by the modem, and 
indicates that it is permissible to begin transmission 
of a message. When using a modem, CTS follows the 
off-to-on transition of RTS after a time delay. 

C22

43

GND

GROUND 

A22

44

TXD4

TRANSMIT DATA (serial port 4) - data to be 
transmitted is furnished on this line to the modem 
from the terminal. 

C23

45

GND

GROUND