RS-422
Connections
Manual Documentation Number: ESP901-902_0508m
Appendix B
75
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 Pk – 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
Serial Server 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 66.
RS-422 Connections in a DB-9 Connector
