|
CHAPTER 6
RS232
CABLING INFORMATION
6.1 DB9
Connector
The signal assignments for a standard
DB25 connector are shown below :
|
DB9
Pin # Signal Name
|
RS-232C
Name
|
Signal
Direction
|
|
1 Data
Carrier Detect(DCD)
|
CF
|
Input
|
|
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
|
|
9 Ring
Indicator(RI)
|
CE
|
Input
|
|
|
To
connect the PCCOM 2 port adapter to other DATA TERMINAL EQUIPMENT
(DTE) devices, we recommend using a DCE to DTE connection as shown
below :
|
6.2 DB25 Connector
User can use DB9 to DB25 connector to transfer DB9
signals to DB25.
The communication interface follows the EIA RS232 standard. The signal assignments for a standard DB25
connector are shown below :
|
DB25
Pin # Signal Name
|
RS-232C
Name
|
Signal
Direction
|
|
1 Chassis
Ground(GND)
|
AA
|
Common
|
|
2 Transmit Data(TxD)
|
BA
|
Output
|
|
3 Receive Data(RxD)
|
BB
|
Input
|
|
4 Request
to Send(RTS)
|
CA
|
Output
|
|
5 Clear
to Send(CTS)
|
CB
|
Input
|
|
6 Data
Set Ready(DSR)
|
CC
|
Input
|
|
7 Signal
Ground(SG)
|
AB
|
Common
|
|
8 Data
Carrier Detect(DCD)
|
CF
|
Input
|
|
20 Data Terminal Ready(DTR)
|
CD
|
Output
|
|
22 Ring Indicator(RI)
|
CE
|
Input
|
25
- PIN D - SHELL
|
6.3 Null Modem
Connections: RS232
If the
software supplier or operating system does not specify a
particular cable configuration, we recommend you use the following
ˇ§null
modemˇ¨ cable when XON/XOFF is utilized.
If hardware handshaking is necessary, use the following
cable:
Some serial devices have the buffer control signal on pin
19, in which case pin 6 on the host is connected to pin 19 on the
remote device.
6.4
Modem
Connection
A straight through cable is required,
e.g. pin 2 to pin 2, pin 3 to pin 3, etc.
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