Advantech UNO-4683, Руководство пользователя

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UNO-4683User Manual 16
2.4 RS-232/422/485 Interface (COM1, COM2)
The UNO-4683 offers two RS-232/422/485 serial communication inter-
face ports: COM1 and COM2. Please refer to Appendix A.2 for their pin
assignments. The default setting of COM1 and COM2 are RS-232.
2.4.1 OXuPCI952 UARTs with 128 bytes FIFO
Advantech UNO-4683 comes with Oxford OXuPCI952 UARTs contain-
ing 128 bytes FIFOs.
2.4.2 RS-422/485 Detection
In RS-422/485 mode, UNO-4683 automatically detects signals to match
RS-422 or RS-485 networks. (No jumper change required)
2.4.3 Automatic Data Flow Control Function for RS-485
In RS-485 mode, UNO-4683 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 conve-
niently build an RS-485 network with just two wires. More importantly,
application software previously written for half duplex RS-232 environ-
ments can be maintained without modification.
Note: Windows usually recognize the COM ports start from
COM3, so these two ports might be named as COM3
and COM4 in Windows. The function will not be affected
and user can also change the name in the Windows
Device Manager easily.