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UNO-3285C User Manual
Chapter 2
H
ardware
F
unctionality
2.2.1
RS-232/422/485 Interface (COM1 & COM2)
UNO-3285C offers two serial communication interface port.
SW1 for COM1(RS-232/422/485) switch
SW2 for RS485/422 receiver termination setting
SW3 for COM2(RS-232/422/485) switch
The COM ports default setting is RS422/485. It can also be switched to RS232 mode
manually.
In RS-422/485 mode, the UNO-3285C automatically detects signals to match RS-
422 or RS-485 networks.
In RS-485 mode, the UNO-3285C automatically detects the direction of incoming
data and switches its transmission direction accordingly. So no handshaking signal
(e.g. RTS signal) is necessary. This lets you conveniently build an RS-485 network
with just two wires. More importantly, application software previously written for half
duplex RS-232 environments can be maintained without modification.
2.2.2
SW1/SW2/SW3 Dip Switch Setting According to Placement
Dip switch definition:
Bit 1: on
Bit 1: off
