The BLS 2321 is a high-performance RS-232 card with a 16C550-style UART that features 16-byte transmit and receive buffers to help guard against loss of data in your busy system. The card may be addressed as COM1: to COM4: or any other I/O address you choose from 000 up to 3F8 hex. The DB-9M port is capable of operating at speeds up to 460kbaud.
The serial card is compatible with all application software that communicates with a standard serial port using an 8250 or 16C450 UART (the UARTs which virtually all PC's use for serial ports).
Drivers are automatically and instantly disabled (and receivers enabled) after transmission of the stop bit. Drivers and receivers may also be controlled with data bits 0 and 1 by writing to the base address+7 for the port (MetraByte COM-485 protocol compatible). RTS and CTS flow control is supported as well. Convenient on-board jumpers allow for 220-ohm termination as needed for each driver and receiver.