5. ROUTER DESIGN
5.8.6
Serial Port RS232
The DB9 Female connector is used for this interface.
Pin
Signal mark
Description
Data flow direction
1
DCD
Data Carrier Detect
Output
2
RXD
Receive Data
Output
3
TXD
Transmit Data
Input
4
DTR
Data Terminal Ready
Input
5
GND
System Ground
—
6
DSR
Data Set Ready
Output
7
RTS
Request to Send
Input
8
CTS
Clear to Send
Output
9
RI
Ring Indicator
NC
Table 9: Connection of RS232 connector
Figure 19: RS232 connector
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