A
Table A-1. EIA-232-D Interconnections
Pin | Signal | Signal Name and Description | |
Number | Mnemonic | ||
| |||
|
|
| |
|
|
| |
1 | Not used. | ||
|
|
| |
2 | TXD | TRANSMIT DATA - data to be transmitted is furnished on | |
|
| this line to the modem from the terminal. | |
|
|
| |
3 | RCD | RECEIVE DATA - data which is demodulated from the | |
|
| receive line is presented to the terminal by the modem. | |
|
|
| |
4 | RTS | REQUEST TO SEND - RTS is supplied by the terminal to the | |
|
| modem 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 - CTS is a function supplied to the | |
|
| terminal by the modem which indicates that it is permissible | |
|
| to begin transmission of a message. When using a modem, | |
|
| CTS follows the | |
|
| delay. | |
|
|
| |
6 | DSR | DATA SET READY - data set ready is a function supplied | |
|
| by the modem to the terminal to indicate that the modem is | |
|
| ready to transmit data. | |
|
|
| |
7 | SIGNAL GROUND - common return line for all signals at | ||
|
| the modem interface. | |
|
|
| |
8 | DCD | DATA CARRIER DETECT - sent by the modem to the | |
|
| terminal to indicate that a valid carrier is being received. | |
|
|
| |
Not used. | |||
|
|
| |
15 | TXC | TRANSMIT CLOCK - this line clocks output data to the | |
|
| modem from the terminal. | |
|
|
| |
16 | Not used. | ||
|
|
| |
17 | RXC | RECEIVE CLOCK - this line clocks input data from a | |
|
| terminal to a modem. | |
|
|
| |
18,19 | Not used. | ||
|
|
| |
20 | DTR | DATA TERMINAL READY - a signal from the terminal to | |
|
| the modem indicating that the terminal is ready to send or | |
|
| receive data. | |
|
|
| |
21 | Not used. | ||
|
|
|
User’s Manual |