Configuration
Sealevel Systems
485I
Page
7
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
