Advantech UNO-3072L, User Manual, Page: 21 / 64

13 Chapter 2
2.2 RS-232 Interface (COM1~COM2)
The UNO-3072Loffers two industrial standard RS-232 serial communica-
tion interface ports: COM1 and COM2. Please refer to Appendix A.4 for
their pin assignments.
The IRQ and I/O address range of COM1 and COM2 are listed below:
COM1: 3F8
H
, IRQ4 COM2: 2F8
H
, IRQ3
2.3 RS-232/422/485 Interface (COM3~COM4)
The UNO-3072Loffers two industrial RS-232/422/485 serial communica-
tion interface ports: COM3 and COM4. Please refer to Appendix A.5 for
their pin assignments. The default setting of COM3 and COM4 are RS-
422/485. (Please refer to section 2.3.4 for how to determine RS-232 or
RS-422/485)
2.3.1 16C550 UARTs with 16-byte FIFO Standard
Advantech UNO-3072Lcomes with 16C550 UARTs containing 16 bytes
FIFOs.
2.3.2 RS-422/485 Detection
In RS-422/485 mode, UNO-3072Lautomatically detects signals to match
RS-422 or RS-485 networks. (Refer to section 2.3.5)
2.3.3 Automatic Data Flow Control Function for RS-485
In RS-485 mode, UNO-3072Lautomatically 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 easily
build an RS-485 network with Data+, Data- and Ground. More impor-
tantly, application software previously written for full-duplex RS-232
environments can be maintained without modification.