User manual

15 Chapter 2
2.4 RS-232 Interface (COM1,COM2)
The UNO-4672 offers two standard RS-232 serial communication inter-
face port: COM1 and COM2. Please refer to A.2 for pin assignments. The
IRQ and I/O address of COM1 and COM2 are listed below:
2.5 RS-232/422/485 Interface (COM3~COM10)
The UNO-4672 offers eight RS-232/422/485 serial communication inter-
face ports: COM3 to COM10. Please refer to Appendix A.2 for their pin
assignments. The default setting of COM3 to COM10 are RS-232.
2.5.1 OXmPCI954 UARTs with 128 bytes FIFO
Advantech UNO-4672 comes with Oxford OXmPCI954 UARTs contain-
ing 128 bytes FIFOs.
2.5.2 RS-422/485 Detection
In RS-422/485 mode, UNO-4672 automatically detects signals to match
RS-422 or RS-485 networks. (No jumper change required)
2.5.3 Automatic Data Flow Control Function for RS-485
In RS-485 mode, UNO-4672 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.
Table 2.7: IRQ and I/O Address for COM1,COM2
COM No. IRQ I/O Address
COM1 IRQ4 3F8H
COM2 IRQ3 2F8H