Распиновка, расположение выводов и внешний вид последовательного интерфейса:
DEC Dual RS-232
Found on the DEC Multia and DEC UDB (Universal Desktop Box). It contains two Serial ports on one connector. The 1st Port is located on the normal pins, and the 2nd port is located on some «spare» pins.
(at the computer)
25 PIN D-SUB MALE at the computer.
PinPortNameDirDescription
1
n/c
Not connected
2
1
TXD

Transmit Data
3
1
RXD

Receive Data
4
1
RTS

Ready To Send
5
1
CTS

Clear To Send
6
1
DSR

Data Set Ready
7
1+2
GND
—
Ground
8
1
DCD

Data Carrier Detect
9
n/c
Not connected
10
n/c
Not connected
11
2
DTR

Data Terminal Ready
12
2
DCD

Data Carrier Detect
13
2
CTS

Clear To Send
14
2
TXD

Transmit Data
15
n/c
Not connected
16
2
RXD

Receive Data
17
n/c
Not connected
18
n/c
Not connected
19
2
RTS

Ready To Send
20
1
DTR

Data Terminal Ready
21
n/c
Not connected
22
1
RI

Ring Indicator
23
2
DSR

Data Set Ready
24
n/c
Not connected
25
2
RI

Ring Indicator
Note: Direction is DTE (Computer) relative DCE (Modem).
Contributor:
Joakim Цgren, Greg A. Woods
Source:
Tommy’s pinout Collection csgrad.cs.vt.edu/~tjohnson/pinouts by Tommy Johnson
Digital UDB Information brouhaha.com/~eric/computers/udb.html by Eric Smith
Copyright © The Hardware Book Team 1996-2004.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2002-01-13