Documentation Number 3PCIOSD2x-3903 Manual
Appendix B
B-1
B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104
B&B Electronics Ltd – Westlink Comm. Pk. – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445
Appendix B:
RS-232 & RS-422/485 Pinouts
Table 1: RS-232 Pinouts
Table 2: RS-422/485 Pinouts
With 2-wire RS-485 mode operation, your connection cable must
jumper TD(A) to RD(A) and TD(B) to RD(B). Connect from TD(A)
and TD(B) to the Data A( ) and Data B(+) wires of your RS-485
network.
Note that the EIA RS-422 Specification labels data lines with an "A"
and "B" designator. Some RS-422 equipment uses a " " and "+"
designator. In almost all cases, the "A" line is the equivalent of the
" " line and the "B" line is the equivalent of the "+" line.
More
information on RS-
422 communications can be found in B&B’s free
RS-422/485 Application Note
(available on our websites).
Name
Description
Direction
DB9M
Pin
DCD
Data Carrier Detect
Input
1
RD
Receive Data
Input
2
TD
Transmit Data
Output
3
DTR
Data Terminal Ready
Output
4
GND
Signal Ground
------
5
DSR
Data Set Ready
Input
6
RTS
Request to Send
Output
7
CTS
Clear to Send
Input
8
NC
Not Connected
------
9
Name
Description
Direction
DB9M
Pin
RD (A)
Receive Data A
Input
1
TD (B) +
Transmit Data B
Output
2
TD (A)
Transmit Data A
Output
3
GND
Signal Ground
------
5
RD (B) +
Receive Data B
Input
9
