ADLINK C485 - Manual (Page 43)

C422
• 31
6
C422 Card Usage
1. DIP SWITCH SW1:
This is a 4-bit DIP switch. Bits 1 and 2 are used to set card number. Default is
set ON to set in first card. Bits 3 and 4 are used to set port interface type. Bit 3
is used for port A and bit 4 is used for port B. Default is ON for a RS422 in-
terface. Set to OFF for RS485.
2. Jumpers JP3 and JP6:
This is jumper to insert (remove) the 120ohm terminator resistor in the
RS422/485 interface. JP3 is used for port A and JP6 is used for port B. When
the jumper is shorted, the terminator resistor inserted. When the jumper is
open, the terminator resistor is removed from interface. Default is no termi-
nator resistor (jumper open).
3. Usage in RS485 interface mode:
When using the RS485 interface, set the DIP switch in SW1 to OFF. Short pin
2 and pin 3 on the DB9 connector for the DATA+ signal. Short pin 4 and pin 6
for the DATA- signal. Users can also use our TB485 converter for a DB9
connector to 3 terminal blocks for DATA+, DATA- , and GND connections.