Non-Isolated RS232 to RS422/RS485 converter
The IC-485S converter can operate in:
RS422 mode: Point to point (2 devices), with two twisted pairs.
RS485 mode: Multidrop on one twisted pair cable,
Simplex: when any device transmits, the others receive only

Features
• In RS485 mode, data transmission direction must be controlled by the RTS Signal (i.e. it is not automatic).
For Automatic direction control see the Trycom units or units listed below from Renu.
• DCE/DTE Selectable
• Point to Point, Multidrop, and Simplex/Duplex Link Selectable
• Four Wire Full Duplex / Two Wire Half Duplex
• Compact Size
• D25 Female connector
• Supports baud rates up to 115.2kbps.
• Monitor Mode on IC-485S

Data transfer can take place at up to 1200 metres over four or two wire cable for full or half duplex, respectively.
In RS485 (2-wire) mode up to 32 receivers can be set up in a multidrop installation, making for a cost effective network configuration.
The RS485 side remains in receive mode until switched to transmit mode by Request to Send (RTS) on the RS232 side.

The IC-485S can obtain power from the RS232 port.
For better line driving capability a mains Adaptor is included
(9VDC, 200mA, with small DC cylindrical plug, 3.5mm dia., centre +ve)