Intelligent RS-485 and RS-422 Adaptors
6
Technical Information
This section of the manual details the pinouts of the Intelligent RS-485
and RS-422 Adaptors.
RS-232 Connector
The female DB-25 connector on the Intelligent RS-485 and RS-422
Adaptors is designed to plug straight into a DB-25 or DB-9 serial port
on your PC, using a standard PC serial cable. Listed below are the
connector pinouts, along with the equivalent pins on both DB-25 and
DB-9 PC serial port connectors, in case you want to make your own
cable.
Pin Function
DB-25 on PC
DB-9 on PC
2
Data from PC
2
3
3
Data to PC
3
2
7 Signal
Ground
7
5
Note that the Intelligent RS-485 and RS-422 Adaptors use only the
transmit and receive data lines and signal ground. However, since
some PC’s may require the RS-232 handshaking lines to be correctly
set, the Intelligent RS-485 and RS-422 Adaptors connects the RTS and
CTS lines together (pins 4 and 5), and the DSR, CD and DTR lines
together (pins 6, 8 and 20).
RS-485 Connector
The RS-485 port on the Intelligent Adaptor is a standard DB9 Female
connector, wired as follows:
Pin Function
1 & 2 Power Supply -ve
3 Protective
Ground
4 & 5 Power ve
6 & 7 RS-485 B (+ve)
8 & 9 RS-485 A (-ve)