User manual

UNO-4673A/4683 Series User Manual 16
2.4.4 Terminal Resistor (SW6,SW8)
The onboard termination resistor (120 ohm) for COM1, COM2 can be used for long
distance transmission or device matching. (Default Open.) Please also refer to Table
2.9 for the mapping table of Jumper and COM port.
2.4.5 RS-232/422/485 Selection
COM1, COM2 support RS-232, RS-422 and RS-485 interfaces. The system detects
RS-422 or RS-485 signals automatically in RS-422/485 mode. To select between
RS-422/485 and RS-232 for COM1, COM2, adjust CN12, CN14 and Table 2.9 shows
the mapping table.
Jumper settings for RS-422/485 interface: (CN12, CN14)
Figure 2.10 RS-422/485 Jumper Setting
Jumper settings for RS-232 interface: (Default setting) (CN12, CN14)
Figure 2.11 RS-232 Jumper Setting
Table 2.10: Jumper setting of terminal resistor
DIP Status Description
1
ON Add terminal resistor on Tx+/Tx- of RS-422 or Data+/Data- of RS-485
OFF No terminal resistor (Default)
2
ON Add terminal resistor on Rx+/Rx- of RS-422
OFF No terminal resistor (Default)
Table 2.11: Mapping table of Jumper/DIP for COM port
COM port
Jumper for RS-232 and
RS-422/485 selection
SW3 DIP switch for
Auto-flow control
Jumper for
Terminal Resistor
COM1 CN12 DIP1 SW6
COM2 CN14 DIP2 SW8