PCI 3 Port RS232
RS232 Pinouts and Cabling
Chapter 4 Page 35
Chapter 4
RS232 PINOUTS AND PORT
CABLING.
Introduction.
This chapter gives details of the 9 and 25 pin RS232 pin outs,
cabling and connections, with information on how to connect the
serial ports of two PCs and how to make a self-test loop back
connector.
The RS232 Standard.
The RS232 standard is ancient in computer industry terms.
Introduced in 1962, it is now widely established. RS232 is a slow
speed, short distance, single ended transmission system (i.e. only
one wire per signal). Typical RS232 maximum cable length is 50
feet with a maximum data rate of 20K bits per second.
Figure 4-1. RS232 Point To Point Connection.
RS232C STANDARD
1 Driver 1 Receiver
Line Length
Max Data Rate
50 Feet = 15m
20 Kbits/sec
Serial Port Pin Outs.
The pinouts of the 9 and 25 pin Male D connectors are given
below.
D
TTL
Ground
Ground
TTL
R
