Solvline PCI - Manual (Page 60)

60
Multi-4/LPCI VA1
-RS485 Model
1. 25Pin Connector (Female)
2. Mode Change
Select between non-echo mode and echo mode during the installation of the device
driver. The default is non-echo mode.
3. Connection
 RT: 120 ohm (If there is no serious noise, termination resistors are not required)
 RS485, like LAN, adopts a half duplex bus where the host is not divided from
terminals.