Serial Ports - Matrox 4Sight X Installation And Hardware Reference

I/O interfaces 93

Serial ports

Matrox 4Sight X integrates two serial ports, the driver and the receiver of which
are always enabled. Each interface is controlled by a Universal Asynchronous
Receiver-Transmitter (UART) device, which converts serial data into parallel data
when receiving information. Conversely, when transmitting information, the
UART converts parallel data to serial data. The motherboard integrates 16550/
16450-compatible UARTs, which feature independently programmable baud
rates and internal 16-byte FIFO memory buffers.
Both serial ports conform to the RS-232 interface standard. RS-232 is capable of
sending and receiving information to and from local devices. Each port supports
a single device (point-to-point connections), and data communication is
single-ended.
The bottom serial port can also be configured for the RS-485 interface standard
by adjusting the unit's internal dip switch to the required interface standard. For
more information on this switch, refer to the Dip switch subsection in the Pinout
descriptions of internal connectors and dip switch section in Appendix B: Technical
reference.
RS-485 can support multiple devices, at faster rates and farther distances. In
addition, data communication is differential.