The PC COM 2 port RS422/RS485 board can
be installed in any IBM PC/XT, PC/AT, PC/386 or hardware compatible system. To accommodate
a variety of operating systems seven jumpers permit maximum flexibility of configuration.
You may select which interrupt (IRQ2 - IRQ7), I/O address you desire.
PC COM 2 port RS422/RS485 adapter provides signal drivers and receivers which can be set
by software or hardware. Since the adapter supports differential communication lines, it
provides longer and more reliable communication quality than RS232. The communication
speed is up to 56K baud and the maximum transmission distance is up to 4000 ft.
Under the RS422 mode, RTS and CTS are used to provide communication flow
control protocol. Under the RS485 mode, only transmission and receive signal are used,
both drivers and receivers can be enabled or disabled by jumper setting or software. This
means the RS485 provides a multipoint communication protocol.