20
A.2 DB25 Female Serial Port Connections
Pin
Name
Description
1
FG
Connected to pin 7
2
TXD
Serial Transmit Data; also used as a power
source
3
RXD
Serial Receive Data (sends XON/XOFF only)
4
RTS
Used as a power source
5
CTS
Clear to Send; connected to +V
7
SG
Signal Ground
8
DCD
Carrier Detect; connected to +V
9
+V in
Used as a power source
11
Secondary Flow Control; accepts flow control
signal (connected to DTR line) (pin 20)
19
SRTS
Secondary Flow Control; accepts flow control
signal (connected to DTR line) (pin 20)
20
DTR
Data Terminal Ready
NOTE
All other pins are unconnected.
