Operations Manual
PCCOM PCI 8 port universal RS232 card
DECISION Computer International
15
CHAPTER 6
R
R
S
S
2
2
3
3
2
2
C
C
A
A
B
B
L
L
I
I
N
N
G
G
I
I
N
N
F
F
O
O
R
R
M
M
A
A
T
T
I
I
O
O
N
N
6.1 DB9 Connector
The communication interface follows the EIA RS232 standard. The
signal assignments for a standard DB9 connector are shown below:
DB9
Pin # Signal Name
RS-232C
Name
Signal
Direction
2 Receive Data(RxD)
BB
Input
3 Transmit Data(TxD)
BA
Output
4 Data Terminal Ready(DTR) CD
Output
5 Signal Ground(SG)
AB
Common
6 Data Set Ready(DSR)
CC
Input
7 Request to Send(RTS)
CA
Output
8 Clear to Send(CTS)
CB
Input
