User manual

15 UNO-4673A/4683 Series User Manual
Chapter 2 Hardware Functionality
2.3.2 Wiring Diagram of the Relay
Figure 2.9 Event Relay Connection
2.4 RS-232/422/485 Interface (COM1, COM2)
The UNO-4673A/4683 series 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-4673A/4683 series comes with Oxford OXuPCI952 UARTs contain-
ing 128 bytes FIFOs.
2.4.2 RS-422/485 Detection
In RS-422/485 mode, UNO-4673A/4683 series 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-4673A/4683 series automatically detects the direction of
incoming data and switches its transmission direction accordingly. So no handshak-
ing 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.
Note! Windows usually recognize the COM ports start from COM3, so these
two ports might be named as COM3 and COM4 in Windows. The func-
tion will not be affected and user can also change the name in the Win-
dows Device Manager easily.