RS-422 Connections
Manual Documentation Number: ESP904-4513m
Appendix B
71
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 –
www.bb-elec.com
B&B Electronics Ltd – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 –
www.bb-europe.com
A
A
P
P
P
P
E
E
N
N
D
D
I
I
X
X
B
B
:
:
R
R
S
S
-
-
4
4
2
2
2
2
C
C
O
O
N
N
N
N
E
E
C
C
T
T
I
I
O
O
N
N
S
S
ESP904 DB-9 Pin-outs in RS-422 Mode
RS-422
Signal Name
Direction
RS-422
DB9M
Pin
Receive Data A (−)
In
RXDA (−)
1
Receive Data B (+)
In
RXDB (+)
2
Transmit Data B (+)
Out
TXDB (+)
3
Transmit Data A (−)
Out
TXDA (−)
4
Signal Ground
---
GND
5
Clear to Send A (−)
In
CTSA (−)
6
Clear to Send B (+)
In
CTSB (+)
7
Request to Send B (+)
Out
RTSB (+)
8
Request to Send A (−)
Out
RTSA (−)
9
Figure 63. RS-422 Connections in a DB-9 Connector
