Specifications

44
Schneider Electric
20 mA CL – RS232 – RS422 –
RS485 links (continued)
The DB9-DB25 physical connection
Some terminals and computers may have a DB9 type RS-232-C serial connector. In
the figure above, the RS-232-C serial connection uses a DB9 to DB25 cable.
Correspondence between a DB9 and a DB25 connector.
DB9 pinout diagram
E70511
DB9 Male
DB25 Female RS-232-C
DB9 to DB25 serial cable
Computer
Interface
DTE
DCE
13
1
25
14
5
1
9
6
DB25 (PIN) DB9 (PIN)
1n/a
23
32
47
58
66
75
81
12 N/a
20 4
22 9
E52487
1
2
3
4
5
6
7
8
9
CD
DSR
RXD
RTS
TXD
CTS
DTR
RI
carrier detection
data set ready
receive data
request to send
transmit data
clear to send
data terminal ready
ring indicator
SG
signal ground
Guide to Integration
Modbus / Jbus