B-2
Appendix B
Documentation Number 3PCIO1-0903 Manual
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
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.
See Chapter 2 for example connections.
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 the B&B
Electronics
RS-422/485 Application Note
(available on our
website).
Table B.3: RS-422/485 Pinouts
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
