
21
RS232C
Host (DB9)
Printer (DB9)
Signal
Description
Pin
Pin
Description
Signal
CD
Carrier Detect
1
1
Provide 5V Power
+5V
RxD
Receive
2
2
Receive
RxD
TxD
Transmit
3
3
Transmit
TxD
DTR
Data Terminal Ready
4
4
No Connection
NC
GND
Ground
5
5
Ground
GND
DSR
Data Set Ready
6
6
Pull High
Hi
RTS
Request to Send
7
7
Request to Send
RTS
CTS
Clear to Send
8
8
Clear to Send
CTS
CI
9
9
Pull High
Hi
1
2
3
4
5
6
7
8
9
Pin
Signal
Description
1
+5V
Provide 5V Power
2
RxD
Receive
3
TxD
Transmit
4
NC
No Connection
5
GND
Ground
6
Hi
Pull High
7
RTS NC
Request to Send
8
CTS
Clear to Send
9
Hi
Pull High