Advantech UNO-3200G Series, Руководство пользователя

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9 UNO-3200G Series User Manual
Chapter 2
H
ardware
F
unctionality
Figure 2.2 Serial Interface (COM1, COM2)
2.2.1 RS-232/422/485 Interface (COM1 & COM2)
UNO-3200 series 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
In RS-422/485 mode, the UNO-3200 series automatically detects signals to match
RS-422 or RS-485 networks.
In RS-485 mode, the UNO-3200 series automatically detects the direction of incom-
ing data and switches its transmission direction accordingly. So no handshaking sig-
nal (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.