8
© Sealevel Systems, Inc. 2104 Manual | SL9092 9/2021
Configuration
Electrical Interface Selection
The port on the
485I
has the ability to be used in both half and full duplex RS-422/485 applications.
This is selectable through DIP-
switch SW1. The chart below describes each of the switch position’s function.
Please refer to the following page for switch setting examples. Switch SW1, in the “ON” position, either
enables, adds, or connects, based on the function of the switch position listed below. Switch SW1, position
OFF, disables, removes, or disconnects .
SW1
Function
1
RS-485 Two Wire Auto Enable/Disable
2
Echo Enable/Disable
3
Adds or removes the 120-ohm termination
4
Adds or removes the 1K ohm pull-up resistor in the RS-422/RS-485 receiver circuit
(Receive data only)
5
Adds or removes the 1K ohm pull-down resistor in the RS-422/RS-485 receiver
circuit (Receive data only)
6
Connects the TX+ to RX+ for RS-485 two wire operation
7
Connects the TX- to RX- for RS-485 two wire operation
8
Not Used
