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USB SINGLE-PORT HUB (RS-422/485)
4. Configuration
4.1 Electrical Interface Selection
The port on the USB Single-Port Hub (RS-422/485) can
be used as RS-530/422/485, RS-422, or 2-wire RS-485.
This is selectable via the DIP-switch SW1. The chart
below describes each of the positions’ functions. Please
refer to the next page for switch setting examples.
Switch SW1 ON enables, adds, and connects. SW1
position OFF disables, removes, and disconnects.
SW1
Function
1
RS-485 two-wire auto enable/disable (ON=Enable).
2
Echo enable/disable (ON=Disable).
3
Adds or removes the 120-ohm termination.
4
Adds or removes the 1 Kohm pull-up resistor in the
RS-422/RS-485 receiver circuit (Receive data only).
5
Adds or removes the 1 Kohm pull-down resistor in the
RS-422/RS-485 receiver circuit (Receive data only).
6
Connects TX+ to RX+ for RS-485 two-wire operation.
7
Connects TX- to RX- for RS-485 two-wire operation.
8
Not used.
