E

EIA-232-D Interconnections

 

 

Table E-1. EIA-232-D Interconnections

 

 

 

 

Pin

Signal

 

Signal Name and Description

Number

Mnemonic

 

 

 

 

 

1

 

 

CHASSIS GROUND. Not always used. See section Proper

 

 

 

Grounding.

 

 

 

 

2

TxD

 

TRANSMIT DATA. Data to be transmitted; input to the modem

 

 

 

from the terminal.

 

 

 

 

3

RxD

 

RECEIVE DATA. Data which is demodulated from the receive

 

 

 

line; output from the modem to the terminal.

 

 

 

 

4

RTS

 

REQUEST TO SEND. Input to the modem from the terminal

 

 

 

when 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.

 

 

 

 

5

CTS

 

CLEAR TO SEND. Output from the modem to the terminal to

 

 

 

indicate that message transmission can begin. When a modem is

 

 

 

used, CTS follows the off-to-on transition of RTS after a time

 

 

 

delay.

 

 

 

 

6

DSR

 

DATA SET READY. Output from the modem to the terminal to

 

 

 

indicate that the modem is ready to transmit data.

 

 

 

 

7

SIG-GND

 

SIGNAL GROUND. Common return line for all signals at the

 

 

 

modem interface.

 

 

 

 

8

DCD

 

DATA CARRIER DETECT. Output from the modem to the

 

 

 

terminal to indicate that a valid carrier is being received.

 

 

 

 

9-14

 

 

Not used.

 

 

 

 

15

TxC

 

TRANSMIT CLOCK (DCE). Output from the modem to the

 

 

 

terminal; clocks data from the terminal to the modem.

 

 

 

 

16

 

 

Not used.

 

 

 

 

17

RxC

 

RECEIVE CLOCK. Output from the modem to the terminal;

 

 

 

clocks data from the modem to the terminal.

 

 

 

 

18, 19

 

 

Not used.

 

 

 

 

20

DTR

 

DATA TERMINAL READY. Input to the modem from the

 

 

 

terminal; indicates that the terminal is ready to send or receive

 

 

 

data.

 

 

 

 

21

 

 

Not used.

 

 

 

 

E-2

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Motorola MVME187 manual Table E-1. EIA-232-D Interconnections, Pin, Signal Name and Description, Number Mnemonic