The USB-COMi is
a USB to RS-485 converter. It
allows easy serial port expansion without requiring IRQ, DMA, or I/O port
resources. The USB-COMi allows the user to easily and economically connect
RS-485 devices to a host using USB. The RS-485 communications standard is
used by DGH sensor based data acquisition modules and many industrial
USB-COMi is based on a single chip USB UART for transferring serial data
over the Universal Serial Bus without the need for card-slots. The
converter has an internal 128 byte transmit buffer FIFO and a 384 byte
receive buffer FIFO. It supports baud rates of up to 230K. External power
is not required since USB-COMi takes its power from the USB bus.
Connection to USB is via a 3-foot detachable USB cable. Connection to
RS-485 is thru the converters DB-9 male connector.
The converter is housed in a plastic enclosure designed for rugged
can interface all DGH RS-485 modules to a host
using a USB connection. When using the USB-COMi with a DGH module or any
RS-485 device that requires wiring, DGH recommends itsí CA-3 cable. The
CA-3 is a 3-foot serial cable with a female DB-9 connector and tinned
wires ready for connection to RS-485.