RS-232, RS-422, RS-485 Connections
47
Manual Documentation Number: LWS300A-1105m
Appendix D
Black Box Corporation - 1000 Park Drive - Lawrence, PA 15055-1018
www.blackbox.com
-- Tech Support and Ordering: 724-746-5500 - Fax: 724-746-0746
A
A
p
p
p
p
e
e
n
n
d
d
i
i
x
x
D
D
:
:
R
R
S
S
-
-
2
2
3
3
2
2
,
,
R
R
S
S
-
-
4
4
2
2
2
2
&
&
R
R
S
S
-
-
4
4
8
8
5
5
C
C
o
o
n
n
n
n
e
e
c
c
t
t
i
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s
s
DB-9M
Pin
RS-232
Signal
RS-232
Designation
DTE
1 Carrier
Detect
DCD
In
2
Receive Data
RXD
In
3
Transmit Data
TXD
Out
4
Data Terminal Ready
DTR
Out
5
Signal Ground
GND
---
6
Data Set Ready
DSR
In
7
Request To Send
RTS
Out
8
Clear To Send
CTS
In
9 Not
connected NA NA
Figure 18. RS-232 Connections in a DB-9 Connector
RS-232, RS-422, RS-485 Connections
48
Manual Documentation Number: LWS300A-1105m
Appendix D
Black Box Corporation - 1000 Park Drive - Lawrence, PA 15055-1018
www.blackbox.com
-- Tech Support and Ordering: 724-746-5500 - Fax: 724-746-0746
DB-9M
Pin
RS-422/485
Signal
Label DTE
1
Transmit Data (-)
TX A(-)
Out
2
Transmit Data (+)
TX B(+)
Out
3
Receive Data (+)
RX B(+)
In
4
Receive Data (-)
RX A(-)
In
5 Ground
GND
---
6
7
8
9
Figure 19. RS-422/485 Connections in a DB-9 Connector
